Identify the genotype for this pedigree chart

Lets say that the genotypes are:

Male affected:XbY

Male unaffected: XaY

Female  affected: XbXb

Female carrier: XaXb

Female unaffected:XaXa

P: XbY  x  XaXa

F1: XaXb  XaXb  XaY  XaY The middle square is female carrier.

P:XbY  x  XaXb

F1: XaXb  XbXb  XaY  XbY The left square is affected female.

P:XaY  x  XbXb

F1: XaXb  XaXb  XbY  XbY The right square is affected male.

the answer is "a.) well–developed vascular system."

explanation:

the answer would be 2, if crossing over doesn’t occur 2 out of 4 of the daughter cells will have that allele.

hope this : )