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: Unhealthy. Sentence 1: Lana knew that sushi was healthy. Sentence 2: So she went to a sushi restaurant. Sentence 3: But after she finished her sushi, she saw someone eating mochi. Sentence 4: She decided to order some. Choices: a. But the color turned out being too bright and saturated. b. But she felt guilty when she got home.
a