Which are the following best describes topsoil

your question asks which of the following, were there options to choose from?

c- cold periods in earth's history during which glaciers covered much of the surface.

explanation:

the major pests we deal with are insects, weeds and fungal diseases. a pesticide is a product, whether organic or chemical, used to kill the target pest. there are other techniques gardeners should use that can prevent the severe infestations that make the use of pesticides necessary