Griffith's experiments along with Avery, MacLeod and McCarty helped to determine the transforming factors of Pneumococcus bacteria. Using heat-killed S-strain bacteria and one particular fraction of the cell lysates, they were able to demonstrate that _____ and not ______ was responsible for the basis of lethality of the strain.

a. proteins, DNA
b. DNA, proteins
c. deoxyribonuclease, mucous coat
d. polysaccharides, proteins

I assume the answer is "b" because DNA indeed is resposible for the basis of lethality of the strain. am I right?