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: Catching Up. Sentence 1: I met an old friend for lunch. Sentence 2: We laughed and talked for 2 hours. Sentence 3: We showed off pictures of our families. Sentence 4: We talked about our kids. Choices: a. I'm happy for them, they both deserve it. b. We promised to meet again soon.
b