I need the answer thanks.

I just looked it up, and I believe the correct answer is B) To examine the need for additional fertilizers.

Explanation:

Scientists are still not completely sure how to grow all crops...

Therefore, they are still figuring out all the vitamins the soil needs to make sure it grows right.

I hope I could help! :)

the wetland preservation movement began in the u.s. in earnest with the clean water act (cwa) of 1972. although not specifically written to protect wetlands, the cwa is comprised of a series of regulations designed to prevent pollutants from contaminating u.s. waters.