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: Clutch. Sentence 1: I had to learn how to drive a stick. Sentence 2: At first I could not go into first gear uphill very well. Sentence 3: I was on my way back from the DMV. Sentence 4: The car behind me backed up. Choices: a. Then I could go up the hill. b. He forgot to check on the cookies!
a