Given the task definition and input, reply with output. 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: The Toy Train. Sentence 1: The men loved playing with their toy trains. Sentence 2: They built tracks and bridges. Sentence 3: The model railroads were very intricate systems. Sentence 4: The men had great plans for the future. Choices: a. They wanted to expand the railroad across the whole yard. b. Edward was able to become the star of the soccer team.
a