Answer:
C
Step-by-step explanation:
Beneficial means:
Something good happening
We can solve this question by just going through the answers, saying if they are good or bad:
A. Genetic disorders often kill or severly deform one in a species, so BAD
B. If it hinders their ability to survive, then especially if an endangered population, the species could go extinct, so BAD
C. Genetic variation ensures that different animals in a species have different traits to help them survive. So GOOD