Fifty years ago, genetic testing did not exist. If we wanted to prove whether someone was related, our best option was blood typing. Now, Elvis Presley was a wildly famous musician who died in 1977. Before his death, it was rumored he fathered a child with someone other than his wife whilst they were living in Hawaii. Prior to Elvis's death, this same woman would take her son to visit him there at least once a year. She also had blood tests done to prove Elvis was the father and tests showed it was possible. Her grandson is alive now, and looks very much like Elvis as you can see below. The grandson is on the left and Elvis is on the right. They have the same O+ blood type, sing beautifully, and both play the guitar. If you were using blood type to determine whether Elvis (whose blood type is O+) was the father of someone, which of these blood types would not have been possible for any of his children? Type A -
Type B +
Type O-
Type AB+