Major reason for H5N1 not to become a global pandemic is: (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
Answer is A. 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