Context: In a group of rainbow trout, some individuals have a greenish-brown body and others have a blue body. In this group, the gene for the body color trait has two alleles. The allele for a greenish-brown body (B) is dominant over the allele for a blue body (b).
A certain rainbow trout from this group has the homozygous genotype bb for the body color gene.
Based on this information, what is this trout's phenotype for the body color trait?
A. a blue body
B. a greenish-brown body
Select the correct answer from the given choices and respond with the letter of the chosen option.

A