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
Inability to perform any work without discomfort is 
Select and explain. 
A. NYHA 1, B. NYHA 2, C. NYHA 4, D. NYHA 3
C: NYHA 4
Answer: C: NYHA 4 
Explanation: New York Heart Association (NYHA) Classification
Importance: Scale used for quantification of degree of functional limitation imposed by Congestive health failure (CHF)