Confirming Continuity over an Interval Practice Test

No; $\lim_{x\to1^-}Q(x)=0$ and $\lim_{x\to1^+}Q(x)=1$, so the limit does not exist.

No; $\lim_{x\to1}Q(x)=1$ but $Q(1)=0$.

No; $Q(1)$ is undefined.

No; $\lim_{x\to1}Q(x)=-1$ but $Q(1)=0$.

Yes; $\lim_{x\to1}Q(x)=0$ exists and equals $Q(1)=0$.