D is the answer to this question. It can be complicated to estimate the frequency of alleles but as long as you know the right formula in order to solve the question, this is possible. The formula that can be used for this is: p + q = 1 p2 + 2pq + q2 = 1.

To make it easier for you, you should always start by computing for the q2 then push through with the other things that you have to know. The moment that you know q2, you can already get the square root and find out what q is. Once you have gotten the right answer to this, you have already gotten the frequency for the recessive allele.