The correct option is A DNA, protein
Hershey and Chase wanted to check if it was the DNA or the protein of the bacteriophage that was injected as genetic material into the bacterial cells. For this, they cultured bacteriophage in two different media - one containing radioactive sulphur 35S (sulphur being a constituent of certain amino acids) to label the protein coat of the bacteriophage, and another containing radioactive phosphorus to label their DNA core. They could then let these radiolabelled bacteriophages infect bacterial cells. If radioactive phosphorus 32P was found in the daughter phage particles (after multiplication within the bacterial cells), they could figure out that the genetic material transmitted is DNA; and if radioactive sulphur was found in them, it could be guessed that protein is the genetic material that gets transmitted.