Definition: 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'.
Input: Sentence 1: Officer Lang answered the call when it came to the station. Sentence 2: The caller said a bomb was planted in the police station. Sentence 3: An FBI agent told Lang to keep the caller on the phone. Sentence 4: The FBI agent traced the call to a cell phone 3 miles away. Sentence 5: But the phone was a prepay, they couldn't identify the caller. Choices: a. The SUV. b. Terrorist Threats.

b