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.

Title: Alec's Ball. Sentence 1: Alec loved to play with his ball. Sentence 2: It was blue with yellow stripes. Sentence 3: One day, Alec went outside with his ball. Sentence 4: He kicked the ball so hard it went rolling down the hill. Choices: a. He put the new endings in the books and shelved them again. b. Alec ran after it and found it lying next to a tree.
b