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: darkness. Sentence 1: Dan was afraid of the darkness. Sentence 2: Specifically, he had trouble of walking home at night. Sentence 3: Dan seeked help from a therapist. Sentence 4: The therapist advised him on how to beat his fear. Choices: a. Dan beat his fear and was able to face the darkness without trouble. b. Joan drove her new red Mitsubishi all day.
a