Given the task definition, example input & output, solve the new input case.
In this task, you are given a question containing a blank (_) and two options. You should pick the best option to answer the question. Please answer with "A" or "B".
Example: Katrina gave Christine a stuffed animal for their birthday, but _ already had this one. (A) Katrina (B) Christine
Output: B
Since the blank is someone who received the gift and already had a stuffed animal, the answer must be "Christine".

New input case for you: The healthy man thanked Logan but not Robert because _ helped him change his life and become healthier. (A) Logan (B) Robert
Output:

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
A