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: Tom was at the lake with friends. Sentence 2: They all wanted to go swimming. Sentence 3: The water was really cold. Sentence 4: Tom didn't want to get in. Sentence 5: It took him a long time to build up the courage to do so. Choices: a. Coffee. b. Cold Water.

b