This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pathology
Which of the following is non-modifiable risk factor for CHD 
Select and explain. 
A. Diabetes, B. Smoking, C. Hypeension, D. old age
D: old age
Answer: D: old age 
Explanation: Nonmodifiable (Constitutional) Genetic abnormalities,Family history,Increasing age.Male gender Modifiable Hyperlipidemia Hypeension Cigarette smoking Diabetes Inflammation (Robbins Basic Pathology,9th edition,pg no.336)