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: Yesterday was Johnny's birthday. Sentence 2: His parents decided to throw him a party. Sentence 3: All of his little friends came. Sentence 4: They ate cake and ice cream and played games. Sentence 5: As he opened his gifts, his parents surprised him with a new bike. Choices: a. An Ineffective Weight Loss Diet. b. Johnny's Surprise.

b