This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition and health, Subject name: Social & Preventive Medicine
To define a health problem, prevalence of corneal xerosis should be - 
Select and explain. 
A. >1%, B. >0.5%, C. >0.01%, D. >0.05%
C: >0.01%
Answer: C: >0.01% 
Explanation: - corneal xerosis a serious problem in which cornea appears dull, dr and non wettable and eventually opaque. - To define a health problem, prevalence of corneal xerosis should be more than 0.01%. Reference : Park's textbook of preventive and social medicine, 23rd edition, pg no:616 <\p>