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: The Tuna. Sentence 1: I could hear the outboard motor before I saw the boat at our dock. Sentence 2: My father's wide grin told me that he had a successful fishing trip. Sentence 3: He heaved the silvery gray, enormous fish onto the dock. Sentence 4: It was a tuna, the largest any of us had ever seen. Choices: a. As a fisherman's daughter, I knew that we would have tuna for dinner. b. He happily put his trophy on his shelf at home.
b