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: Sunrise. Sentence 1: Martin mostly traveled during the night. Sentence 2: It had been a long time since he had seen the sun rise. Sentence 3: One night, he decided to stay up so he could witness it. Sentence 4: He was very tired, so it was difficult for him to stay awake. Choices: a. After seeing the sun rise in the morning, he felt accomplished. b. The next day he ran his shirt on.
b