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: Zoo. Sentence 1: Bobby and Sandy went to the zoo. Sentence 2: They saw all kinds of animals. Sentence 3: Around noon, they went to the concession stand for lunch. Sentence 4: After lunch, they walked around some more. Choices: a. Before leaving, Bobby and Sandy looked at the gift shop. b. The boys drove off from the mall at the end of the day.
Output:
a