What are the possible genotypes and phenotypes of the children of a cross between a male with type AB blood and a female type A blood whose father was type O blood?

there is no uncertainty about the genotype of either parent. A parent of blood type AB has the codominant IA and IB alleles. ... Their children could be in blood groups A or B, but not AB or O

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.