Which Statement Describes the First Direct Evidence for Involvement of Cellular

Which statement describes the first direct evidence for involvement of cellular oncogenes in human tumors?

A) Normal human cells could be transformed by the src-containing Rous sarcoma viruses.
B) DNA extracted from a human bladder carcinoma was able to transform recipient mouse cells in culture.
C) DNA extracted from a mouse carcinoma was able to transform recipient human cells in culture.
D) DNA extracted from a human carcinoma was able to transform recipient chicken cells in culture.