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: Pathology
Most common cause of renal tumor in adult is? 
Select and explain. 
A. Family history, B. Smoking, C. Obesity, D. Hypeension
B: Smoking
Answer: B: Smoking 
Explanation: Answer- B. SmokingImpoant risk factors for RCC are smoking (most significant), obesity, hypeension, asbestos exposure, estrogen therapy, CRF, tuberous sclerosis and familial conditions (Von Hippel-Lindau syndrome).