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.
Q: Title: It's not me, it's you. Sentence 1: You know, when you break up, they say it is me, not you. Sentence 2: Well, my boyfriend and I had problems for a while. Sentence 3: I turned myself inside out trying to please him to no avail. Sentence 4: Then i found the craigslist message where he was looking for man. Choices: a. Then I knew it was a problem with him, not me. b. His mother laughed at him and told him to be open-minded.
A:
a