Instructions: 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: Mountain Trip. Sentence 1: Tim went mountain climbing. Sentence 2: It was a person challenge. Sentence 3: He made it almost all the way to the top. Sentence 4: He gave up shortly before the peak. Choices: a. Tim wants to go back and finish. b. Elena was presented her new doll on her birthday.
Output:
a