A genetics researcher finds that a form of human albinism in a certain population is controlled by the recessive allele, a, for the absence of skin pigment and the completely dominant allele, A, for presence of skin pigment. If the recessive allele occurs in 30% of this population, what percent of the population has skin pigment but also carries the recessive allele?
21 percent
42 percent
91 percent
51 percent