In electron micrographs of hsv infection, it can be seen that the intact virusinitially reacts with cell surface proteoglycans, then with specific receptors. this is later followed by viral capsids docking with nuclear pores. afterward, the capsids go from being full to being "empty." which of thefollowing best fits these observations?

a. viral capsids are needed for the cell to become infected; only the capsids enterthe nucleus.
b. the viral envelope mediates entry into the cell, the capsid mediates entry intothe nuclear membrane, and the genome is all that enters the nucleus.
c. only the genetic material of the virus is involved in the cell's infectivity, and isinjected like the genome of a phage.
d. the viral envelope is not required for infectivity, since the envelope does notenter the nucleus