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'.

Sentence 1: A friend gave me an old car. Sentence 2: This car had a big problem. Sentence 3: The front door would not open. Sentence 4: I tried hard with all my might. Sentence 5: I finally realized that I had to give it a small tug for it to open. Choices: a. The car door. b. Aim.
a