Given the task definition and input, reply with output. 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: Secret letter. Sentence 1: Jim bought a coat at a thrift store. Sentence 2: He wore it out of the store. Sentence 3: When he put his hand in the pocket he felt something. Sentence 4: He pulled out an old letter. Choices: a. Jim had no idea that this was in the coat when he bought it! b. He spent the rest of the boat ride hugging a toilet.
a