A Number of Viruses Often Include a Similar Set of Symptoms

Multiple Choice

A number of viruses often include a similar set of symptoms when they cause an infectious disease state (fever,headache,fatigue,runny nose) .Why would they all cause the same symptoms if they're different viruses?

A) They all possess the same basic virulence genes and molecules,so they all trigger the same responses.
B) The symptoms are associated with the immune system's response,NOT the molecules from the pathogens themselves.Our responses against viruses are fairly similar,regardless of virus type,so the symptoms are similar.
C) Most viruses infect the upper respiratory tract-this leads to the common set of symptoms listed above.Only a few viruses infect areas away from this region.
D) Viruses specifically infect mainly epithelial membranes.As such,the virally induced reaction is similar in different areas of the body due to the same basic cell types (epithelial cells) being infected in each area.