ABO blood grouping of humans is an example of co-dominance. Homozygotes (IAIA and IBIB) express either the A or the B phenotype. Heterozygotes (IAIB) express both phenotypes equally and the IAIB individual has blood type AB. Blood type O is the result of the genotype IOIO: this blood type is considered the recessive trait and IO is the recessive allele for blood type. Imagine a genetic cross between two people, blood type AB. What is the probability that these people will have offspring with type B blood? A) 0% B) 10% C) 25% D) 50%