Knudsen and colleagues also noted that persons with hereditary retinoblastoma that had been treated successfully lived on but then had a higher frequency of developing osteosarcomas (bone cancers) later in life. This provided further evidence of their theory because

A) osteosarcoma cells express the same genes as retinal cells. B) p53 gene mutations are common to both tumors. C) both kinds of cancer involve overproliferation of cells. D) one of the mutations involved in retinoblastoma is also one of the changes involved in osteosarcoma. E) retinoblastoma is a prerequisite for the formation of osteosarcoma later in life.