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
When an association between two variable is explained by a third variable due to indirect association. It is called as? 
Select and explain. 
A. Cognitive bias, B. Confounding bias, C. Berkessonian bias, D. Indirect bias
B: Confounding bias
Answer: B: Confounding bias 
Explanation: .confounding bias is used as a third variable to explain the association between two variables caused due to indirect association ref:park&;s textbook of preventive and social medicine,22nd edition,pg no 71