The correct option is D Pleiotropy
A condition in which a single gene influences more than one trait is known as pleiotropy. Sometimes one trait will be very evident and others will be less evident. For example, in Drosophila, a gene for white eyes also affects the shape of organs in female responsible for storage of sperms as well as other structures.
When more than two alternative forms of a gene in a population occupying the same locus on a chromosome or its homologue are known as multiple alleles. For example, ABO blood group system in humans.
Linked genes are the ones that occur on the same chromosome and tend to stay together during the formation of gametes.
Recombination is a process by which pieces of DNA are broken and recombined to produce new combinations of alleles. In eukaryotic cells, which are cells with a nucleus and organelles, recombination typically occurs during meiosis.