The sentence as originally written attempts to be concise in its language, but does so at the expense of clarity and understanding. Simply adding in a small phrase to more adequately explain the full meaning of the phrase will greatly improve the sentence. The answer choice which best accomplishes this task is "with the original legislation giving proscribed limits to be used under certain circumstances."

The use of the present participle "having" makes the sentence not actually contain a verb, as a participle links to other verbs to create present action. The word needs to be changed to the present active verb form to make the sentence gramatically correct. "Historians have long noted the sharp discrepancy" is the only answer choice which appropriately makes the correct change.

The use of the present participle "deciding" in this sentence is inappropriate, as the action is in the past. Therefore, the word should be changed to the past participle form. The only answer choice which makes this change is "the group all decided to wear extra layers," making it the correct answer choice.

The underlined portion of the sentence has an inappropriate verb form, with the present tense "is" clashing with the previous use of "was." The verb needs to be changed to match the previous verb in the first part of the sentence. The only answer choice that correctly makes this change is "by anyone who was working for him."

The use of "had not been spoken to" in this sentence is incorrect. The man had not spoken to his close friends, so his friends "had not been spoken to," by the man. The sentence incorrectly makes the man the object of this phrase. The correct answer fixes this by making the man the subject of the phrase and not the object: "he had not spoken to in decades."

The sentence's introductory clause seems to intend to describe the subject "he," but it begins with a verb that doesn't clearly connect to the rest of the sentence and is grammatically incorrect. Introductory clauses can begin with participles, which would make much more sense in this sentence by allowing the start of the sentence to connect clearly to the subject. Of the potential answer choices, only "Having been immersed" omits the incorrect verb and replaces it with a grammatically correct participle. The other answer choices don't make sense: "Immersion having happened" and "Immersion happening" don't clearly connect the first phrase to the subject, and "He who had been immersed" introduces a grammatical error by making the sentence contain two disconnected subjects, "He who had been immersed in the literature since childhood" and "he." The corrected sentence reads, "Having been immersed in the literature since childhood, he maintained an appreciation for it as an adult."

The issue in the underlined portion of the sentence is the use of the verb form "existing," which is a participle and not an actual verb. The word needs to be changed into a form that functions as a verb. "Conflicting desires exist in every single person" is the correct choice among the answers.

The introductory phrase that is highlighted in the sentence describes the condition under which the woman reacted to her son's gift. Therefore, the verb form needs to describe a condition or way of being. Such a form is the present participle, which shows action currently being taken, and the correct answer is "Holding back tears."

The underlined portion of the sentence has a problem with the verb form "eating." The gerund form, used here, is inappropriate, as it is actually a verb that functions as a noun; therefore, the correct answer is "did not want to eat for a few hours."

The use of the verb "confused" creates many different problems in the sentence. By leading off a phrase, the word needs to be in a form that can link the phrase to the first part of the sentence. "Confusing the troops," which uses a past participle to describe the effect of the orders, is the correct answer choice.