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
The number of new cases occurring in a defined population during a specified period of time is called - 
Select and explain. 
A. Period prevalence, B. Point prevalence, C. Prevalence, D. Incidence
D: Incidence
Answer: D: Incidence 
Explanation: None