After Reading the Paragraph Below, Answer the Question(s) That Follow(s)

Multiple Choice

After reading the paragraph below, answer the question(s) that follow(s) .
A woman has been trying to conceive for several years, unsuccessfully. At a fertility clinic, they discover that she has blocked fallopian tubes. Using modern technologies, some of her eggs are removed, fertilized with her husband's sperm, and implanted into her uterus. The procedure is successful, but the couple discovers that their new son is colourblind and has blood type O. The woman claims that the child can't be theirs since she has blood type A and her husband has type B. Also, neither parent is colourblind, although one grandparent (the woman's father) is also colourblind.
-With respect to the possibility that the wrong fertilized egg had been implanted accidentally, you would explain that

A) this is impossible since an egg from another individual would have been rejected by the immune system.
B) this is possible, but there is no way of knowing whether this happened.
C) this is possible and could be determined by genetic analysis of the child.
D) this is possible and could be determined by behavioural testing.