Before dna was discovered, in which materials did scientists think genetic material was stored?

To them, DNA was too simple a molecule to be able to carry that sort of complex information and proteins showed much more variation. However, a series of experiments conducted by various groups of scientists started to reveal that in fact it was DNA, not protein, that carries the genetic   information.  They thought it was protein.    

the answer is d (apex) good luck : ))

the answer for this question would be d. glaciers