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.
Q: Title: Assignment. Sentence 1: Billy received a new work assignment. Sentence 2: He was supposed to make a presentation. Sentence 3: He worked hard all day. Sentence 4: The group really liked it. Choices: a. I was happy to win, but the birthday girl was dismayed. b. They presented together to the client.
A: 
b