It is possible for a child to have the blood type O if the parents have A+ and B+. However, this blood type has the lowest probability of occuring (6.25%),
The highest probability for an offspring with parents like Karent and Jeremy is AB with a chance of 56.25%. Next are A and B each with a chance of 18.75%.
However, if one of the parents is AB, then the chances for an offspring with O blood type is zero.