Definition: 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.
Input: Title: Ex Girlfriend. Sentence 1: John was at the bar with friends. Sentence 2: He noticed his ex girlfriend walked in. Sentence 3: John was mildly upset. Sentence 4: She noticed him. Choices: a. They exchanged pleasantries and moved on. b. She was right, and I've been in choir ever since.
Output:
a