Incompletely dominance is a form of inheritance in which one allele is not completely expressed in a specific trait because of this pattern of inheritance with its paired allele. So, the explanation doesn't fit and A is incorrect.
Codominanceis a oform of inheritance in which both alleles are expressed, even if they are different, so both traits will appear. So, the explanation doesn't fit and B is incorrect too.
Multiple allele refers t when a population has more than two alleles o f the same gene. So, the explanation doesn't fit and D is incorrect too.
Genetic linkage occurs when two genes are lcated close to each othwer in a chromosome and are often inherited together, and that fits the definition that was given. Therefore, the correct answer is C. linked.