Answer: B. 0.77
Step-by-step explanation:
We should note that from the Hardy-Weinberg law, the formula used is:
p²+ 2pq+ q² = 1
From the information given,
p = purple allele
q = red allele
q² = 59/100 = 0.59
Then, the frequency of the red allele that is recessive will be:
q² = 0.59
q= √0.59
q = 0.768.
q = 0.77
Therefore, the correct option is B.