Hereditary retinoblastoma is an autosomal dominant hereditary cancer.Cells from retinal tumors in a child who has this disease possess

A)evidence of non-disjunction in all autosomes.
B)one non-functional copy of the retinoblastoma gene.
C)two non-functional copies of the retinoblastoma gene.
D)trisomy for the retinblastoma gene.
E)a dominant mutation in the retinoblastoma gene.