This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Pneumonic plague is spread by: 
Select and explain. 
A. Bite of infected flae, B. Direct contact with infected tissue, C. Ingestion of contaminated food, D. Droplet infection
D: Droplet infection
Answer: D: Droplet infection 
Explanation: Ans. is. 'd' i. e., Droplet infection