Answer:
The correct answer will be- He showed that transforming material was DNA in organisms.
Step-by-step explanation:
Oswald Avery and colleagues worked on the experiments of Griffith on the transformation process and showed that the transforming material was DNA in Griffith experiment.
They grew the cultures of heat-killed S (virulent) bacteria and added DNases, RNases and proteases to the culture plates. Then R (avirulent) bacteria were added to the cultures. The S bacteria were not found in the cultures with DNases enzymes as DNases denatured the DNA molecule, so bacteria were not transformed.
This showed that DNA is the transforming material in the Griffith experiment.