I think the answer would be pesticides... i see you selected it though. was that a wring answer?
Explanation:
Hormone production and release are primarily controlled by negative feedback. In negative feedback systems, a stimulus causes the release of a substance whose effects then inhibit further release. In this way, the concentration of hormones in blood is maintained within a narrow range.
The Answer is (A)
Because the pesticide will kill off the bugs and weeds but will damage the soil so after the crops you have in the ground now just will not grow there again until 1 year after the pesticide has washed away
hope I helped