Context: This passage describes the flower form trait in rose plants:

In a group of rose plants, some individuals have double flowers and others have single flowers. In this group, the gene for the flower form trait has two alleles. The allele for single flowers (f) is recessive to the allele for double flowers (F).
A certain rose plant from this group has the homozygous genotype ff for the flower form gene.
Based on this information, what is this plant's phenotype for the flower form trait?
A. single flowers
B. double flowers
From the given choices, choose the correct answer and respond with the letter of that choice.

A