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: Drug Dog. Sentence 1: At our apartment, we thought a lady was selling drugs. Sentence 2: People were coming to her window and knocking all night long. Sentence 3: One day, an officer showed up with a drug dog. Sentence 4: He started chasing her cat. Choices: a. We wondered if she had cats to cover for drug dealing. b. Since then, they have been inseparable.
A:
a