Answer:
The alleles for red and white coat color are co-dominant.
Explanation:
Co-dominance is the condition when none of the allele of a gene is dominant. The heterozygous genotype exhibits traits of both alleles. 
In the given example, the offspring have roan coat color in which white hairs are mixed into a base coat of red. Since both the alleles are expressed in heterozygous offspring, the alleles for red and white coat colors are co-dominant over each other. 
 
        
             
        
        
        
both alleles in the heterozygous
genotype are exhibit in the phenotypes.  Allele
is completely dominant over the other, and  it is the phenotype is a blend of the two
homozygous phenotypes, there are more than two forms of the same gene, and
there maybe one more superior form and several different phenotypes
 
        
             
        
        
        
C. Duh. No one has to agree with a successful thesis.