In this task, you're given five sentences, numbered 1 through 5, and two options a and b for possible titles for the story. Your job is to choose the title that better fits the story. Indicate your choice by 'a' or 'b'.

Sentence 1: Will went to a lecture on a controversial subject. Sentence 2: After the talk, they opened things up for a Q-and-A. Sentence 3: Will approached the questioners' microphone. Sentence 4: Will asked the speaker a very tough question. Sentence 5: The speaker was stunned and stumped by Will's insight. Choices: a. Lecture. b. A New Book.
a