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: Social & Preventive Medicine
Major reason for H5N1 not to become a global pandemic is 
Select and explain. 
A. Man to man transmission is rare, B. Route of transmission is not respiratory, C. Does not cause serious disease among humans, D. Restricted to few countries only
A: Man to man transmission is rare
Answer: A: Man to man transmission is rare 
Explanation: Reasons for H5N1 not becoming Global Pandemic

Absence of efficient human to human mode of transmission (Major reason)
Absence of replication in humans
Absence of serious disease in humans