A human male is heterozygous for autosomal genes 'A' and 'B'. He is also hemizygous for haemophile gene 'h'. What percentage of sperms will carry 'abh' genotype?

The correct option is A 12.5%
When a human male is heterozygous for autosomal gene A and B and also a hemizygous for haemophilic gene h then his genotype will be AaBbX${}^h$Y as haemophilia is a X-linked recessive disorder. The gametes produced bfrom this genotype will be abX${}^h$, abY, ABX${}^h$, ABY, AbX${}^h$, AbY,aBX${}^h$ and aBY. So, the total number of sperm carries abh is 1 out of 8 gametes i.e., 1/8 or 12.5%. Thus, the correct answer is option A.