Given the task definition, example input & output, solve the new input case.
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'.
Example: Sentence 1: Marcus needed clothing for a business casual event. Sentence 2: All of his clothes were either too formal or too casual. Sentence 3: He decided to buy a pair of khakis. Sentence 4: The pair he bought fit him perfectly. Sentence 5: Marcus was happy to have the right clothes for the event. Choices: a. Marcus Buys Khakis. b. Marcus Works.
Output: a
Marcus's reasons for buying khakis is established, followed by his purchase of them and reaction.

New input case for you: Sentence 1: Mario swept Carla off her feet by offering her a diamond ring. Sentence 2: She turned around the room as he held her close. Sentence 3: But when he hit the corner of a table, the ring fell. Sentence 4: It rolled on the floor. Sentence 5: And fell between the cracks of the floor. Choices: a. Diamond ring. b. Moving Dan.
Output:
a