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
True statement about influenza A virus: 
Select and explain. 
A. It has a double stranded segmented RNA, B. Pandemics are caused by antigenic drifts, C. Nucleocapsid antibody is not specific, D. Hemagglutinin and neuraminidase are strain specific
D: Hemagglutinin and neuraminidase are strain specific
Answer: D: Hemagglutinin and neuraminidase are strain specific 
Explanation: None