In this task, you're given the title of a five-sentence story, the first four sentences, and two options for the fifth sentence as a and b. Your job is to pick the sentence option that seamlessly connects with the rest of the story, indicating your choice as 'a' or 'b'. If both sentences are plausible, pick the one that makes more sense.
Q: Title: Broken Heart. Sentence 1: Tim had a crush on Sally. Sentence 2: They went to school together for several years. Sentence 3: He finally got the courage to ask her out. Sentence 4: She turned him down because she already had a boyfriend. Choices: a. The friend knew what it was and turned it down. b. Sally lived a wonderful life that Tim always envied.
A:
b