Which of the following exhibits parabolic motion

Aerodynamic and hydrodynamic play a big role

Parabolic motion is going to occur when the object has no other force acting on it besides gravity. In order to do that you would need to be thrown or fall, because if you were standing still on the Earth you would have the Normal Force of the Earth pushing you back, which is the reason why you don't fall through the Earth as a result of gravity. To be more exact it is not that you have no other forces acting on you, but it is that you have no other vertical forces, and that you have a horizontal force. Why is a horizontal force needed? Think about it. If you were to fall with no horizontal force and were of course assuming that there is no winds to give you a horizontal force, what would your fall look like? A straight downward motion fall. Which is not parabolic. 

Now!
A. A Frog Jumping from Land into water
B. A Basketball thrown in a Hoop
C. A flat piece of paper released from a window
D. A Baseball thrown to home plate 

If my earlier explanation didn't help. Think of what the action would look like. 

A frog jumping from land to water would see a wider parable, but it would be a parable. 

A Basketball thrown into a hoop would go up and then back down in that same parabolic shape that you have likely seen at least once in your life. 

A Baseball (or Basketball) thrown to home plate would see a REALLY hard to notice parabolic shape (depending on how fast the initial throw is) but it is there. 

A Flat piece of paper falling will have no horizontal motion and thus will just be a straight downward fall. 

So our answer is, C.

The anwser is: wave a has a greater pitch and frequency.