* A. It lives as a commensal in most humans

* B. It is a common cause of community acquired pneumonia

* C. It is an AIDS defining illness in patients with HIV

* D. It caused pneumonia in malnourished children after World War II

* E. The most sensitive way of making the diagnosis is with a direct immunoflourescence stain on sputum or Bronchoalveolar lavage

Correct Answer: B