Answer:
I believe the answer is:
If both are BB, the child will be BB. If one is BB and one is BO, the child has a 50% chance of being BB and 50% chance of being BO - both of which result in type B.
However, if both parents are BO, there is a 25% chance of BB, a 50% chance of BO, and a 25% chance of OO (which results in type O).
