Steven grows corn in his garden every year. He always uses the same methods, and never adds to or changes the soil in any way. He notices that every year, his corn crop is smaller and smaller, even though the weather hasn’t been any different. What is the explanation for what is happening to Steven’s corn? A. The soil is running out of nutrients.

B. The corn needs more space to grow.

C. The soil isn’t as deep as the year before.

D. Steven is using the wrong type of seeds.