TASK DEFINITION: You are given a question or fill-in-the-blank question, two answer options (Option1 and Option2) and an Explanation. Your task is to find the correct answer (return the string of the correct option, not option1/2) for the given question from the given options and using explanation.
PROBLEM: Question: If Mona is bouncing radar waves off a test car when training to be a policewoman and she notices the frequency of the waves returning to her radar gun is lower then it was before, what is happening to the car she is pointing the gun at? 
 Option1: decreasing in speed 
 Option2: increasing in speed 
 Explanation: 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.

SOLUTION: decreasing in speed

PROBLEM: Question: As waves get smaller the frequency of them 
 Option1: increases 
 Option2: decreases 
 Explanation: Wave frequency can be measured by counting the number of crests or compressions that pass the point in 1 second or other time period. The higher the number is, the greater is the frequency of the wave.

SOLUTION: increases

PROBLEM: Question: When we crumple a rubber band it has 
 Option1: high potential energy 
 Option2: low potential energy 
 Explanation: The more an elastic object is stretched or compressed, the greater its elastic potential energy is.

SOLUTION:
high potential energy