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.

Ex Input:
Title: Snow Day. Sentence 1: Stephen saw the snow come down. Sentence 2: He waited for a phone call. Sentence 3: The school called. Sentence 4: They said school was closed. Choices: a. Stephen celebrated. b. We all went home very happy.

Ex Output:
a

Ex Input:
Title: Counseling or Divorce. Sentence 1: Heather and her husband have been together for twenty years. Sentence 2: He has cheated on her with another woman at least three times. Sentence 3: Finally Heather is started to think that her marriage isn't working. Sentence 4: She thinks long about the various choices that she has to make. Choices: a. Ella wished she'd agreed to go to church sooner! b. Heather decides that maybe they need to try counseling services.

Ex Output:
b

Ex Input:
Title: Lost Book. Sentence 1: Tom got a book from the library. Sentence 2: He forgot to return it. Sentence 3: After a while Tom couldn't remember where he left the book. Sentence 4: Tom called the library to pay for it. Choices: a. He was charged a small fee. b. However, by the end of the season, Lucas had made many friends.

Ex Output:
a