Context: Zoe is sledding with her friends. She notices that some of them go faster down the sledding hill. She wonders what factors affect sledding speed. So, she decides to design an experiment. She has the following supplies available:
access to a small snow-covered hill at the park
a small plastic sled
a large plastic sled
a rubber inner tube sled
a stopwatch
Using only these supplies, which question can Zoe investigate with an experiment?
A. Does a rubber inner tube sled go faster down a small hill or down a big hill?
B. Does a plastic sled or a wooden sled go down a hill faster?
C. Does a rubber inner tube sled or a plastic sled go faster down a hill?
From the given choices, select the correct answer and reply with the letter of the chosen option.

C