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: My school was pretty stingy when it came to fun activities. Sentence 2: It was announced that there would be a field trip, such excitement! Sentence 3: Except it came out that we'd be going to the water treatment plant. Sentence 4: Not only that, we'd have to walk the whole way there! Sentence 5: In the end it turned out my only field trip was a pretty crappy one. Choices: a. A Crappy Field Trip. b. Vet's Life.
Output:
a