Come up with a question and stream of consciousness reasoning that would justify this answer: (A)

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
The question is: The average age of A, B and C is 25 years. If the average age of A and C is 29 years, what is the age of B in years ?
Options:
(A) 17
(B) 35
(C) 20
(D) 32
(E) 21
Stream of consciousness: Age of B = Age of (A + B + C) â€“ Age of (A + C) = 25 Ã— 3 â€“ 29 Ã— 2 = 75 â€“ 58 = 17 years
