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: House. Sentence 1: Tom wanted to buy a house. Sentence 2: He saved his money for many years. Sentence 3: He saw a house that he liked and made an offer on it. Sentence 4: The offer was accepted. Choices: a. Tom moved into the house the following month. b. The document was a perfect alibi, so the man was proven innocent.
a