Context: In a group of Channel catfish, some individuals have a brown body and others have a white body. In this group, the gene for the body color trait has two alleles. The allele B is for a brown body, and the allele b is for a white body.
A certain Channel catfish from this group has a brown body. This catfish has two alleles for a brown body.
Based on this information, what is this Channel catfish's genotype for the body color gene?
A. BB
B. a brown body
Answer with the option's letter from the given choices directly.

A