Respuesta :
Answer:
D. Genetically distinct varieties of corn should be grown so that genetic variation will ensure at least some of the corn plants will be resistant to the corn rust.
Explanation:
Genetic diversity can be rare for selectively bred vegetable varieties, but it is the best method to use to ensure resistance to drought, pests, disease, and cold winters. Without genetic variation, one adverse condition could wipe out whole crop yields for a season.