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 does not connect with the rest of the story, indicating your choice as 'a' or 'b'. If both sentences are plausible, pick the one that makes less sense.

Title: My Brother's Mirror. Sentence 1: My brother is forgetful. Sentence 2: He once broke a mirror in our bathroom. Sentence 3: He didn't clean it up and forgot to tell me about it. Sentence 4: I walked into the bathroom and stepped on the glass. Choices: a. Harry punched the mailman and stuffed his junk mail in his shirt. b. My brother was sorry for forgetting, and helped me clean up the wound.
a