This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidney Stones & Renal Tubular Acidosis, Subject name: Medicine
Which is the most common cause of calcium oxalate stones? 
Select and explain. 
A. Hyperparathyroidism, B. Idiopathic Hypercalciuria, C. Dietary intake of milk-based products, D. Renal tubular acidosis type 1
B: Idiopathic Hypercalciuria
Answer: B: Idiopathic Hypercalciuria 
Explanation: Most common cause of calcium oxalate stones- Idiopathic Hypercalciuria Other causes are- Hyperuricosuria Primary hyperparathyroidism Distal renal tubular acidosis Dietary hyperoxaluria