Can abneg and opos have bpos baby?

Yes, an AB negative (AB-) and an O positive (O+) individual can have a baby with a B positive (B+) blood type. The possible blood types of their child can be A, B, AB, or O, depending on the combination of alleles inherited from each parent. Since the AB parent can contribute A or B alleles, and the O parent contributes an O allele, a B blood type is possible if the child inherits a B allele from the AB parent and an O allele from the O parent. Additionally, the Rh factor from the O+ parent can result in the child being Rh positive or negative.