Final answer:
The law of independent assortment, described by A, asserts that genes sort into gametes independently, forming diverse combinations and contributing to genetic variation in offspring.
Step-by-step explanation:
The correct answer to which best describes the law of independent assortment is A. The factors for each trait are separated independently when sex cells form. The law of independent assortment is an essential principle of genetics first described by Gregor Mendel through his work on pea plants.
This law explains how different genes independently separate from one another when reproductive cells develop. In a dihybrid cross, for instance, the combination of alleles for seed color and seed texture in pea plants assort independently during the formation of gametes. Each allele pairs for different characteristics sort into gametes randomly, leading to a variety of genetic combinations that contribute to genetic diversity in offspring.