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
True morbidity in a population can be calculated by? 
Select and explain. 
A. Sentinel surveillance, B. Passive surveillance, C. Active surveillance, D. Monitoring
C: Active surveillance
Answer: C: Active surveillance 
Explanation: Ans. is 'c' i.e., Active surveillance o True morbidity is calculated by --> Active surveillance o Missing cases are detected by --> Sentinal surveillance