Which type of inheritance involves multiple genes influencing a trait?

Polygenic inheritance is the correct answer because it refers to the phenomenon where multiple genes contribute to the expression of a single trait. This type of inheritance results in a continuous variation of traits, as each gene can have several alleles that interact in various ways to produce a range of phenotypes. A classic example of polygenic inheritance is human height, where multiple genes influence the final height, resulting in a spectrum of heights rather than discrete categories.

Monogenic inheritance, on the other hand, pertains to traits determined by a single gene, which leads to distinct phenotypic categories, such as Mendelian traits like pea color in plants. Simple dominance describes a situation where one allele completely masks the effect of another allele at the same locus, and codominance occurs when two different alleles at a locus are both expressed in the phenotype. Both simple dominance and codominance apply to single genes and do not account for the influence of multiple genes on a trait. This makes polygenic inheritance the appropriate choice when discussing how multiple genes work together to influence a specific characteristic.