What is is called when two forms of a trait are both dominant at the same time?

The answer is Homozygous

Explanation:

Homozygous is a word that alludes to a specific quality that has indistinguishable alleles on both homologous chromosomes. It is alluded to by two capital letters (XX) for an overwhelming attribute, and two lowercase letters (xx) for a latent trait.Alternative types of a given quality are called alleles, and they can be predominant or passive. At the point when an individual has two of a similar allele, regardless of whether predominant or passive, they are homozygous. Heterozygous means having one every one of two unique alleles

the correct option is option d