Given the task definition and input, reply with output. 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: An old friend came to visit me a few days ago. Sentence 2: I hadn't seen him in over a year before that. Sentence 3: When he stopped by he told me he had a gift for me. Sentence 4: The gift he had brought for me was a delicious cheeseburger. Sentence 5: I had a great time eating it with my friend. Choices: a. Eating a cheeseburger. b. 2 Weeks Later.
a