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: Twins. Sentence 1: Anna was a first-time mom. Sentence 2: She had had twins a few weeks earlier. Sentence 3: Two babies proved to be incredibly hard! Sentence 4: Anna was sleep-deprived and miserable. Choices: a. But looking at her twins, she knew it was worth it. b. He was pleased to find he was only 20 miles out of his way!
a