Since Mary has a Type A blood, she is either AA or AO while John is either BB or BO. Since both John's parents are Type AB, he can only have the either A or B as an allele and not O so he is BB. Since John can only give the B allele, all of his children must have the B allele in their blood types. So the adopted one is the child with type A blood.
I believe the correct answer from the choices listed above is option 4. This type of research is often successful in advancing knowledge regarding the functioning of human cells because <span>cellular research using mice can always be applied to human cells since all complex organisms produce the same proteins.</span>
Hope this answers the question. Have a nice day.
