What did the experiment by Avery,MacLeod,and McCarty in 1944 with the R and S strains of Streptococcus pneumoniae demonstrate?

A)DNA was the genetic material in cells.
B)R strain phenotype could spontaneously revert to S strain phenotype.
C)Genetic material from one strain could be transferred to another strain.
D)The ability of these bacteria to kill mice.
E)That some strains of Streptococcus were not pathogenic.