Answer:
Option D, DNA is a transforming factor.
Step-by-step explanation:
It was found by Avery and his team that there is a transforming factor in living organisms which passes on the genetic information from one generation to other and this transforming factor is no other than the DNA. DNA has chromosomes which carries the genetic material responsible for expression of any trait.
Before findings of Avery, it was believed that genetic material was carried through proteins.
Hence, DNA is considered as a transforming factor