You will be given a definition of a task first, then some input of the task.
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: Strong Bubbling Tea. Sentence 1: Ken boiled hot water. Sentence 2: He placed two bags of green tea in a cup with the hot water. Sentence 3: When he drinked all of it, his stomach started to hurt. Sentence 4: Ken had diarrhea for two hours. Choices: a. His kidneys are failing and he only has six months to live. b. After he used the bathroom, he went to sleep.
Output:
b