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: Fall. Sentence 1: I am one of the people who can't get up if they fall. Sentence 2: I had a stroke in the fall of 2011. Sentence 3: Last night I went to the bathroom and the cane slipped on the tile. Sentence 4: I fell and could not get up. Choices: a. Luckily my wife was able to help me up. b. Luckily, her teacher postponed the test.
b