3rd in the series of 3 blood type questions. a man with blood type a marries a woman with blood type b. many years later they both die suddenly, leaving a substantial estate but no will. four people turn up and claim to be the couple's children. one person is a, one b, one ab, and one o. none seem to know each other and each claims the others are frauds. because of your efforts one claimant is left (other than your employer). you notice the other claimant is brach (=has bracydactyly=short broad fingers = rare, dominant condition.) you can earn your fee and settle the case if you can show that . (only one answer for this question)