Context: In a group of dogs, some individuals have short fur and others have long fur. In this group, the gene for the fur length trait has two alleles. The allele F is for short fur, and the allele f is for long fur.
Fido, a dog from this group, has long fur. Fido has two alleles for long fur.
Based on this information, what is Fido's phenotype for the fur length trait?
A. ff
B. long fur
Determine the correct option from the provided choices and reply with its corresponding letter.

B