The best choice is "ear." The relationship between "wheel" and "transmission" is that they are both parts of a car. This is an uncommonly seen relationship (also known as part to part) in which two parts of some larger object are named. Therefore, we must figure out what choice shares the same relationship with the word "eye." We can rule out "face" since an eye is a part of a face, meaning that the relationship would be part to whole which is inappropriate here. We can also rule out the choices "pupil" and "iris" as those are both parts of an eye, which would mean the relationship is whole to part. "See" is an action that you do with an eye—also inappropriate. The remaining option is "ear," which makes sense as an eye and an ear are both parts of a face.

The best answer is "tailpipe." The relationship between "wall" and "floor" is that they are both parts of a house. Likewise, an "engine" and a "tailpipe" are both parts of a car. Considering the other choices, a "car" and a "plane" are both things than have an engine, which would make the relationship part to whole instead of part to part as it should be. A "piston" is a part of an engine (whole to part), and "gasoline" is simply something that goes inside of an engine or powers an engine. Therefore, "tailpipe" makes the most sense here.

Since a keyboard is part of a computer on which letters are printed and people use to write messages, we need to pick out an answer choice in which the first word is part of the second word, and more specifically, a part that involves letters or writing. "Paper is to pen" might be correct if the words were reversed, but as it stands, they are in the wrong order, and while a pen is used to write messages on paper, it is not specifically part of paper; however, since moveable type refers to the part of a printing press on which letters are carved and a printing press can be used to print written works, "moveable type is to printing press" is the correct answer.

Since a ceiling represents the topmost part or upper boundary of a room, we're looking for a pair of words in which the first word describes the upper boundary or the topmost part of the second. "Leaves are to trees" may seem like a good answer initially, but leaves are only part of trees—while they can be found at the top of trees, they don't necessarily have to. Similarly, stalactites are found on the ceilings of caves, but they represent only a feature of the ceiling, not the entire boundary. The best answer is "canopy to forest," as the forest represents the topmost part or upper boundary of a forest.

The wrapper on a piece of candy protects its exterior, so we need to pick out an answer choice that describes what protects the exterior of an orange. While “rind” and “pulp” might each look like a potentially correct answer because each word is associated with oranges, “pulp” means the soft part of a fruit, so it cannot be the correct answer because an orange’s pulp does not protect its exterior; however, “rind” can mean the tough exterior of a fruit. Because orange rind protects its exterior just as a candy’s wrapper protects its exterior, “rind” is the correct answer.

A sector is a portion of a circle—think of a “pie piece” or something of the like. Thus, the analogy could be rewritten, “Just as a sector is part of a circle, so is a segment part of X.” In general, a segment is any potential divided part of an object—in segmented worms, segments of cars, etc. Among the options provided, only “line” provides a suitable “whole,” to which the “part” that is a segment can be compared. All of the other options are broadly related but insufficient.

Sometimes an analogy can be so simple that you will overanalyze it. Do not do so with this question. Icing is merely meant here as the top layer on the cake—nothing further. Thus, the bridge sentence for this analogy could be written, “Just as icing is the top layer on a cake, so froth is the top layer of X.” Froth is the top layer of liquid caused by it being disturbed or sometimes by something like the fermentation of yeast in the liquid.

The ingredients of a recipe are the parts of which it is comprised; therefore, one could fairly write the bridge sentence, “Just as ingredients are the parts of a recipe, so are bristles part of a X.” Now, “bristle” can mean to become angry, but this comes from the description of an animal that is “bristling,” that is, having its hair stand up out of anger or fear. Bristles are a type of stiff hair that are used in brushes, which would be the best option for the “larger thing” of which the bristles are a part.

A district is a part of a given city. For instance, a city might have a “market district” in which a number of food salespeople have shops for selling bulk quantities to potential restaurants in town. There might be an “Italian district” in which a number of Italians live and have set up shops and restaurants, giving the area a distinctive Italian appearance and character. The analogy could thus be rewritten, “As a district is part of a city, so too is an hour part of X.” An hour is part of a day. While it is a period of time, a measure of time, a moment (in the grand scheme, at least), and even “a portion” (of a longer time), it is only part of a day. The analogy requires a part-whole relationship.

Since a yolk is part of an egg, we need to pick out an answer choice in which the first word describes a part of the second word. Either "page is to book" or "finger is to hand" could be the correct answer. Since a yolk is contained within an egg and a page is contained within a book, but a finger is not contained within a hand, "page is to book" is the better answer of the two choices and the correct answer.