Detailed Instructions: In this task, you're given the title of a five-sentence story, the first four sentences, and two options for the fifth sentence as a and b. Your job is to pick the sentence option that seamlessly connects with the rest of the story, indicating your choice as 'a' or 'b'. If both sentences are plausible, pick the one that makes more sense.
Q: Title: Hiking in the Mountains. Sentence 1: Today Ricky was going to visit a new waterfall. Sentence 2: He studied the map carefully and planned his route. Sentence 3: He packed a big bottle of water since it was a hot day. Sentence 4: There was no marked trail so the hike was very slow going. Choices: a. When he first saw the waterfall he felt a sense of joy. b. He found a pair of rolled-up, stinky socks behind his headboard.
A:
a