Answer:
The correct option is C) It makes the overall crop more susceptible to pests or disease.
Step-by-step explanation:
The reduction in genetic variation of a crop plant will cause serious threats to the particular crop population. If the genetic diversity will be low, then threats like a disease or a pest can invade the plant population as a result of which the entire population might become endangered.
Increased genetic variation ensures that some of the varieties might be able to adapt better to the changing threats as a result of which the whole of the population is at very low risk of getting erased.