This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
Secular trend is 
Select and explain. 
A. Long term, B. Sho term, C. Both, D. None
A: Long term
Answer: A: Long term 
Explanation: The term secular trend implies changes in the occurence of diseases (i.e. A progressive increase or decrease)over a long period of time generally several years or decades.(refer pg no: 66 park 23 rd edition)