Question

what term is used to describe a phenomenon in which pests become resistant to a pesticide over time – making farmers apply more and more pesticide each time they spray?
pesticide treadmill
chlorinated hydrocarbons

Explanation:

The "Pesticide treadmill" refers to the cycle where pests develop resistance to pesticides, forcing farmers to use increasing amounts of pesticides. "Chlorinated hydrocarbons" are a type of chemical compound, not related to this phenomenon.

Answer:

A. Pesticide treadmill