Because Viruses Could Not Be Visualized Using Conventional Microscopes Further

Because viruses could not be visualized using conventional microscopes further progress required the development of techniques for isolating,propagating and analyzing viruses. All of the following are true EXCEPT:

A) crystal structure of the tobacco mosaic virus showed that it was made up of RNA and protein
B) viruses were first observed with an electron microscope
C) viral DNA has a different structure from that discovered by Watson and Crick
D) Hershey and Chase demonstrated that the genetic material of some viruses is DNA