Irene and William are having their first child. Irene knows her blood type is A, but William does not know his blood type. However, William knows that his mother and father were B. Their first child is a boy named Gregory. Gregory has type O blood. Of course, Irene and William do not understand how this happened. You could explain this to them using which of the following choices?
a. Irene's genotype is AA, and William's genotype is OO; thus, Gregory expresses the phenotype of O.
b. Irene's genotype is AO, and William's genotype is BO; thus, Gregory expresses the phenotype of O.
c. Because his parents were both type B, William could not be the father of Gregory.
d. Gregory's blood type will need to be checked after his first month of life if the parents want to know his blood type. It takes about a month for the blood type to develop in a newborn child.
e. Since Irene is type A, there had to be a mix-up in the lab report. Gregory should have been type A.
Answer: B