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: Dental
Cross sectional study is implicated in: 
Select and explain. 
A. Study of chronic disease., B. Study of rare disease., C. Study of sudden outbreak., D. All of the above.
C: Study of sudden outbreak.
Answer: C: Study of sudden outbreak. 
Explanation: Cross-sectional:
Gives PREVALENCE.
Studies one point at a time (One point study). Different individual of SAME age group ,studied only once - 1 point study
Is very important in Study of SUDDEN OUTBREAK OF DISEASE.