This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: AIIMS 2018, Subject name: Medicine
Which of the following is the most commonly used drug for management of community acquired pneumonia? 
Select and explain. 
A. Vancomycin, B. Ceftriaxone, C. Azithromycin, D. Streptomycin
C: Azithromycin
Answer: C: Azithromycin 
Explanation: Azithromycin for management of pneumococcal pneumonia Modality Regimen Previously healthy and no antibiotics in past 3 months: A macrolide or Doxycycline (100 mg PO BD) Comorbidities or antibiotics in past 3 months: select an alternative from a different class Fluoroquinolone or A b- lactam plus a macrolide In regions with a high rate of "high-level" pneumococcal macrolide resistance,consider alternatives listed above for patients with comorbidities