Context: In a group of guppies, some individuals have a gray body and others have a golden body. In this group, the gene for the body color trait has two alleles. The allele B is for a gray body, and the allele b is for a golden body.
Undyne, a guppy from this group, has a golden body. Undyne has two alleles for a golden body.
Based on this information, what is Undyne's phenotype for the body color trait?
A. a golden body
B. bb
Answer with the option's letter from the given choices directly.

A