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.

Title: Planned trip. Sentence 1: Jasper had planned his trip to California carefully. Sentence 2: Every day was filled with new exciting things to discover. Sentence 3: When he had a chance to changed his schedule, he refused. Sentence 4: He continued his trip without changing anything. Choices: a. Without realizing it, she stood up and ran to the door. b. Once he got back home, he regretted not having taken any chance.
b