Some question: Which one of the following is a prime number?
Options:
(A) 55
(B) 2
(C) 74
(D) 25
(E) 21
Some stream of consciousness:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
2 is divisible by 1 and itself So, it is a prime number. The answer: (B).