A man with type A blood marries a woman with type B. Their offspring all have type AB blood. The pattern of
inheritance is called

Codominance

Explanation:

Since neither type A blood nor type B is dominant over the other (i.e both are codominant), the offspring of both parents will be with type AB blood.

Thus, codominance explains how the two alleles are present in the Heterozygous individual IAIB, showing they are both fully expressed.

The answer is codominance.

Explanation:

Codominance is where both parents alleles are expressed because none of them can be "masked". This also goes for red and white flowers making a pink flower. Hope this helps!