Question

random fertilization increases genetic variation by:
ensuring only the strongest sperm fertilize the egg
allowing any sperm to fertilize any egg
changing the dna of gametes
preventing nondisjunction

Explanation:

Random fertilization means any genetically unique sperm can fuse with any genetically unique egg, which creates new combinations of genetic material, increasing variation. The other options are incorrect: random fertilization does not select for "strongest" sperm, does not alter gamete DNA, and does not prevent nondisjunction.

Answer:

Allowing any sperm to fertilize any egg