Definition: In this task, you're given five sentences, numbered 1 through 5, and two options a and b for possible titles for the story. Your job is to choose the title that better fits the story. Indicate your choice by 'a' or 'b'.
Input: Sentence 1: The guests all huddled behind the couch. Sentence 2: They were throwing their friend a surprise party! Sentence 3: When he got home, they all jumped out and yelled. Sentence 4: Their friend was so surprised! Sentence 5: It was a great party. Choices: a. The Spaceship. b. The Party.

b