Oswald Avery and colleagues strengthened scientific support that DNA was the transforming factor by replicating the Griffith experiment with some important differences in experimental design.The key difference was:

A)purifying S strain DNA and RNA from other biomolecules.
B)systematically eliminating the impact of classes of S strain biomolecules using enzymatic digestion before mixing with R strain live cells.
C)injecting S strain DNA directly into R strain cells and observing the change in phenotype.
D)Avery used Escherichia coli rather than Streptococcus as it is easier to transform.
E)All of the answer options are correct.