Context: In a group of rock pocket mice, some individuals have dark fur and others have light fur. In this group, the gene for the fur color trait has two alleles. The allele F is for dark fur, and the allele f is for light fur.
Lollipop, a rock pocket mouse from this group, has dark fur. Lollipop has one allele for dark fur and one allele for light fur.
Based on this information, what is Lollipop's phenotype for the fur color trait?
A. dark fur
B. Ff
Pick the correct answer from the listed options and provide the letter of the selected option.

A