You Are Called to the Emergency Room to Evaluate an Otherwise

You are called to the emergency room to evaluate an otherwise healthy 18-year-old female whose chief complaints are fever,malaise,and difficulty breathing.As you enter the room,the physician informs you that he suspects community-acquired pneumonia.The most likely causative agent would be:

A) Legionella
B) Chlamydia
C) H.influenzae
D) S.pneumoniae