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
Kuppuswami's classification is based on all except – 
Select and explain. 
A. Income, B. Occupation, C. Education, D. Type of house
D: Type of house
Answer: D: Type of house 
Explanation: Type of house is not included in this index
Residential address does form an index for socio economic status in another index by Holingshed in USA. This index includes three variables

Education
Occupation
Residential address