Its theories hope your doing good on your quiz
I believe he is looking for an allele
An allele is a variant form of a gene. Some genes have a variety of different forms, which are located at the same position, or genetic locus, on a chromosomes. Humans are called diploid organisms because they have two alleles at each genetic locus, with one allele inherited from each parent.
The correct answer is that variable number repeats are used in DNA tests; they have hundreds of possible lengths. Eye color is determined by variations in a person's genes. Most of the genes associated with eye color are involved in the production, transport, or storage of a pigment called, melanin. Eye color is directly related to the amount and quality of melanin in the front layers of the iris.
Im almost certain the answer is D but theres a chance I might be wrong