Answer: (2) Alfred Hershey and Martha Chase

Explanation-

In the Hershey and Chase experiment, radioactive phosphorus (32P) and and radioactive sulphur (32S) was used to culture bacteriophages. These bacteriophages were then made to infect bacterial cells. It was seen that the bacterial cells contained radioactive viral DNA, but not radioactive viral protein because DNA contains phosphorous, but protein does not. Hence this experiment proved that the DNA, and not protein, is the genetic material passed from the virus to bacteria.

Their experiments in 1952 using bacteriophages provided clear evidence that DNA is the genetic material responsible for heredity.