In a group of bitter melon plants, some individuals have dark brown seeds and others have light brown seeds. In this group, the gene for the seed color trait has two alleles. The allele D is for dark brown seeds, and the allele d is for light brown seeds. A certain bitter melon plant from this group has dark brown seeds. This plant has one allele for dark brown seeds and one allele for light brown seeds.

Based on this information, what is this bitter melon plant's phenotype for the seed color trait?

(A.) Dd (B.) dark brown seeds