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: Night Work. Sentence 1: Bob was hired to work nights at an oil refinery in his home town. Sentence 2: A first it wasn't hard going to bed early and giving up a social life. Sentence 3: After the first year he missed his friends and family events. Sentence 4: He slowly became depressed and began drinking more. Choices: a. Tom had a lot of fun by the end. b. After five years of night work he finally quit and found a new job.
b