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: How did that happen. Sentence 1: Tim had bent down to tie his shoe. Sentence 2: While he was bent over a bowl of cereal fell off the table. Sentence 3: Milk splattered everywhere. Sentence 4: The bowl had broke into many pieces. Choices: a. I was twenty minutes late and had to serve a detention. b. Tim had accidentally hit the bowl with his elbow.
b