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 Professor. Sentence 1: Doctor Hamilton was a new professor. Sentence 2: He taught English classes at the college. Sentence 3: He was known to be very tough. Sentence 4: Nancy came to him and said she was confused. Choices: a. He hooked up his drawing tablet and used it instead. b. He took the time to explain the material to her.
a