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: Joe climbed high into the apple tree when he heard an ominous crack. Sentence 2: The branch beneath his feet rocked and swayed. Sentence 3: He grabbed the branch above just as the lower branch gave way. Sentence 4: Clinging tightly, he shouted for his sister to bring the ladder. Sentence 5: Safely down, he saw mushrooms on the trunk, warning of a rotten tree. Choices: a. Basketball match. b. Rotten Tree.

b