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: Surgery
A 60 yr old smoker came with the history of painless gross hematuria for one day. The investigation of choice would be : 
Select and explain. 
A. Urine routine and microscopy, B. Plain x-ray KUB, C. USB KUB, D. Urine for malignant cytology
D: Urine for malignant cytology
Answer: D: Urine for malignant cytology 
Explanation: None