Answer: <em>C. Compare the percentages of radish seeds that germinate in different types of soil</em>
Explanation:
The hypothesis you are trying to prove is that the soil type affects the germination of radish seeds, to do this you would need to compare the germination rates of radish seeds in different soil types to see if there is an actual difference on the germination rates of the seed.
You are testing the affects of different soils on the germination of seeds, therefore, you must compare different types of soil. The other answers don't have correlation to different types of soils, and are incorrect.
