Context: This passage describes the Tobiano patterning trait in horses:

In a group of horses, some individuals have Tobiano patterning and others do not. In this group, the gene for the Tobiano patterning trait has two alleles. The allele for having Tobiano patterning (B) is dominant over the allele for not having Tobiano patterning (b).
Casper is a horse from this group. Casper has the homozygous genotype BB for the Tobiano patterning gene.
Based on this information, what is Casper's phenotype for the Tobiano patterning trait?
A. not having Tobiano patterning
B. having Tobiano patterning
From the given choices, pick the correct answer and respond by indicating the letter of the correct option.
Answer: B