Context: In a group of rabbits, some individuals have black fur and others have brown fur. In this group, the gene for the fur color trait has two alleles. The allele F is for black fur, and the allele f is for brown fur.
Muffin, a rabbit from this group, has brown fur. Muffin has two alleles for brown fur.
Based on this information, what is Muffin's genotype for the fur color gene?
A. brown fur
B. ff
From the given choices, choose the correct answer and respond with the letter of that choice.

B