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: Murder Mystery. Sentence 1: We went to a dinner and show one night. Sentence 2: There was a murder mystery on stage. Sentence 3: Someone was killed, and we had to solve the murder. Sentence 4: It was very entertaining. Choices: a. He is getting extra exercise. b. My son guessed the murderer correctly, and our meal was free.

Ex Output:
b

Ex Input:
Title: Talker. Sentence 1: Harry is a 78 year old retired professor who lives in the building. Sentence 2: He is very lonely and tries to talk to people. Sentence 3: A new concierge just came on last week. Sentence 4: Harry talked to him for 2 hours. Choices: a. Because of his fact acting, he saved more than half this of his crops. b. The concierge finally told Harry he was busy.

Ex Output:
b

Ex Input:
Title: treasure map. Sentence 1: John went on a trek in a forest. Sentence 2: He finds a map and he assumes it to be a treasure one. Sentence 3: John follows the map. Sentence 4: John goes into a cave. Choices: a. Before she knew it it was dark. b. John finds treasure.

Ex Output:
b