In peas, the smooth allele is dominant over the wrinkled allele. A plant with round peas was crossed to a plant with wrinkled peas and all of the resulting plants had smooth peas. What are the genotypes of the parents in this cross?
◦ RR × rr
◦ RR × Rr
◦ Rr × rr
◦ Rr × Rr
◦ rr × rr