What is the blood type of the child born with AB blood type and O blood type?

According to ABO blood type system can be divided into A blood type, B blood type and O blood type, general AB blood type and O blood type people, blood contains A type gene and B type gene, these are two dominant genes, O gene is an invisible gene, so in inheritance will appear AO and BO situation, so the child may only be A blood type or B blood type.