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
Most severe pain in ureteric stone is seen in cases of? 
Select and explain. 
A. Oxalate stones, B. Triple phosphate, C. Cystine stone, D. Uric acid stone
A: Oxalate stones
Answer: A: Oxalate stones 
Explanation: Ans. is 'a' i.e., Oxalate stones