You will be given a definition of a task first, then some input of the task.
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 seamlessly connects with the rest of the story, indicating your choice as 'a' or 'b'. If both sentences are plausible, pick the one that makes more sense.

Title: Hang Gliding. Sentence 1: Frank couldn't believe he was going to do this. Sentence 2: Here he was up on the mountain. Sentence 3: He strapped himself into the hang glider with his instructor. Sentence 4: 1, 2, 3 and off they went! Choices: a. Frank soared over the valley that day, having an amazing time. b. Anna felt refreshed when she returned.
Output:
a