Avery and Colleagues Purified a White Substance as the Transforming

Avery and colleagues purified a white substance as the transforming principle.Treating this substance with enzymes that destroyed RNA, protein, or polysaccharides did not affect its ability to transform cells, but enzyme that degrades DNA destroyed the transforming ability.These results suggested that

A) their transforming principle was not entirely pure.
B) the transforming principle appeared to be DNA.
C) the test for transformation was not accurate.
D) a single gene could transform bacterial cells.
E) both DNA and proteins are required for transformation.