Why Is It Important to Preserve the Genes of the Wild

Why is it important to preserve the genes of the wild relatives of crop plants?

A) Beneficial genes from the wild relatives may be transferred into crop plants.
B) It is not important because the human population no longer eats wild foods.
C) By preserving the genes, we can control the growth of the wild relatives, which threaten our crop plants.
D) The wild relatives are the food sources for all domestic animal species.
E) It is not important because the wild species have all become extinct.