Why Are Early Symptoms of a Francisella Tularensis Infection Often

Why are early symptoms of a Francisella tularensis infection often difficult to diagnose?

A) Patient symptoms are the only indication that leads to a diagnosis.
B) The bacteria do not grow in culture.
C) Early symptoms can vary based on how the bacteria are transmitted.
D) Symptoms are often mild and go unnoticed.
E) Symptoms progress so slowly it can be months before the patient seeks medical care.