Given the task definition and input, reply with output. You are given a short paragraph, a question and two choices to answer from. Choose the correct answer based on the paragraph and write the answer(not the key).

Paragraph: A: As the car approaches the radar gun, the reflected microwaves get bunched up in front of the car. Therefore, the waves the receiver detects have a higher frequency than they would if they were being reflected from a stationary object. The faster the car is moving, the greater the increase in the frequency of the waves.
 Question: Tina is speeding on the highway, and a cop is sat on the road with a radar gun to see who to pull over. The cop's gun begins to detect a low frequency, with waves reflected being bunched up. The car was going 
 Choices: A)faster 
B)slower
slower