The diagnosis of severe sepsis must include a(n) :

A) known pathogen.
B) fever.
C) organ dysfunction.
D) HIV-positive status.

Organ dysfunction is a key component of the diagnosis of severe sepsis. While a known pathogen may be helpful in identifying the type of infection causing sepsis, it is not required for the diagnosis. A fever may be present, but is also not necessary for the diagnosis. HIV-positive status is not relevant in making the diagnosis of severe sepsis.