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
"Incidence" is defined as - 
Select and explain. 
A. Number of new cases occurring in a defined population, B. Total cases (new+old) occurring in a defined population, C. Number of exposed developing the disease in a defined population, D. None of the above
A: Number of new cases occurring in a defined population
Answer: A: Number of new cases occurring in a defined population 
Explanation: Ans. is 'a' i.e., Number of new cases occuring in a defined population