Which of the above parents could have a baby with blood type O?

use the first picture attachment for both questions

1. Which of the above parents could have a baby with blood type O?

a.Parents 1 and 2
b.Parents 2 and 4
c.Parents 2 and 3
d.Parents 1 and 4
 
I said D, am i correct?

2.The predicted phenotypic ratio for the children of parents 3 is

a.1/4 type A, 1/4 type B, 1/4 type AB, and 1/4 type O
b.1/2 type AB and 1/2 type O
c.1/2 type A and 1/2 type B
d.1/4 type A, 1/2 type O, and 1/4 type B

3.  A woman with blood type AB blood has a child with the same blood  type. What are the possible genotypes of the father?

4.If a man has type AB blood and a woman has type A blood, what possible blood types could their children have? Give the expected percentages for all phenotypes. 1 mark for correct phenotypes.