Context: This passage describes the wing type trait in fruit flies:

In a group of fruit flies, some individuals have normal wings and others have vestigial wings. In this group, the gene for the wing type trait has two alleles. The allele for normal wings (N) is dominant over the allele for vestigial wings (n).
A certain fruit fly from this group has the homozygous genotype nn for the wing type gene.
Based on this information, what is this fly's phenotype for the wing type trait?
A. normal wings
B. vestigial wings
From the given choices, pick the correct answer and respond by indicating the letter of the correct option.

B