Answer: B) he made his first mistake in step 5. He used the statement he was trying to prove as a reason.
The goal of the proof is to show that SP = SQ. This should be the very last line of the proof. We cannot use this as support or reasoning for other steps (because we haven't proven it to be true or not). This is known as circular reasoning. The term "equidistant" means "equally distant", so in other words, Jaime is trying to prove that S is equally distant to the points P and Q.
