The most conclusive evidence that viruses cause cancers is provided by
A) finding oncogenes in viruses.
B) some liver cancer patients having had hepatitis.
C) cancer following injection of cell-free filtrates.
D) the presence of antibodies against viruses in cancer patients.
E) treating cancer with antibodies.

Question

Quizplus · Accepted Answer

Cancer following injection of cell-free filtrates is direct evidence that viruses can cause cancer, as it demonstrates that the infectious agent in the filtrate can induce cancer in a host.

The Most Conclusive Evidence That Viruses Cause Cancers Is Provided