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: Forgotten milk. Sentence 1: I went to the store to buy milk. Sentence 2: I walked through the store and put many items in the cart. Sentence 3: I went to the register, checked out, and drove home. Sentence 4: When i went to put my items away, I realized I had forgotten the milk. Choices: a. I was frustrated during my drive back to the store. b. He wound up having a lot of fun there.
a