Context: In a group of cats, some individuals have a hairy body and others have a hairless body. In this group, the gene for the body hair trait has two alleles. The allele for a hairless body (b) is recessive to the allele for a hairy body (B).
Millie is a cat from this group. Millie has the homozygous genotype bb for the body hair gene.
Based on this information, what is Millie's phenotype for the body hair trait?
A. a hairless body
B. a hairy body
Identify the correct choice from the options below and respond with the letter of the correct option.

A