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: Artie's Guesses. Sentence 1: Artie liked to try to guess how much people weighed. Sentence 2: He met Christine, and told her that he thought she weighed 200 pounds. Sentence 3: Christine was mortified and offended. Sentence 4: She slapped Artie. Choices: a. Artie now keeps his guesses to himself. b. So her mother stopped that behavior.
a