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
Analysis of routine measurement aimed at detecting changes in the environment? 
Select and explain. 
A. Surveillance, B. Isolation, C. Monitoring, D. RCT
C: Monitoring
Answer: C: Monitoring 
Explanation: Monitoring is the performance and analysis of routine measurements aimed at detecting changes in the environment or health status of population.