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: Peanut Allergy. Sentence 1: Marissa had just started her new job at the fudge counter of a store. Sentence 2: Her coworker told her not to give samples to children. Sentence 3: But when a small boy came begging, Marissa couldn't resist. Sentence 4: She didn't see what harm could be caused by giving him a tiny piece! Choices: a. Tim was never satisfied with the answer. b. When she noticed him covered in hives later, she realized her error.
b