Instructions: 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: Charles was curious of what it would be like to experience addiction. Sentence 2: He went to the store and bought a carton of cigarettes. Sentence 3: He smoked a pack every day, liking it more with each pack. Sentence 4: A month after he began smoking, he unsuccessfully tried to quit. Sentence 5: Unable to quit, Charles still smokes a pack of cigarettes every day. Choices: a. Addiction. b. The Snake.
Output:
a