Context: Brian and his classmates are growing tomato plants in the school garden. He wonders what factors affect how tomato plants grow. So, he decides to design an experiment. He has the following supplies available:
three different types of tomato seeds
one bag of potting soil
five identical clay pots
water
Using only these supplies, which question can Brian investigate with an experiment?
A. Does a certain kind of tomato plant grow taller when planted in a clay pot or in a plastic pot?
B. Which type of soil will cause a certain kind of tomato plant to grow the most fruit?
C. Which of the three types of tomato seeds sprouts the fastest?
Determine the correct option from the provided choices and reply with its corresponding letter.

C