Colorado potato beetles cause considerable damage to potato plants. Various insecticides were tested which controlled the beetle population initially, but presently the population is resistant to most of these insecticides. What is most likely the reason for the ineffectiveness of these insecticides in controlling the Colorado potato beetle population? Colorado potato beetles produced chemicals to counter the effect of insecticides.
A. Colorado potato beetles produced chemicals to counter the effect of insecticides.

B. Colorado potato beetles mutated and became resistant to these insecticides.

C. Colorado potato beetles that survived the insecticide produced insecticide-resistant offspring.

D. Colorado potato beetles that received nutrients from potato plants developed insecticide resistance.