At one gene locus in humans there are 2 alleles: one for curly hair and another for straight hair. neither allele is dominant, and heterozygous individuals have wavy hair. at a second gene locus, 3 alleles control abo blood type. the alleles at these 2 gene loci assort independently. a man with straight hair and a blood marries a woman with wavy hair and b blood. their first child has straight hair and o blood. if their second child is a boy with straight hair, what is the probability that he has a blood?
a. 25
b. 35
c. 40
d. 15