This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Surgery
Renal stone which is formed due to proteus infection is ? 
Select and explain. 
A. Calcium oxalate, B. Uric acid, C. Cystine, D. Struvite
D: Struvite
Answer: D: Struvite 
Explanation: Repeat question Triple phosphate or struvite ( Calcium phosphate with ammonium magnesium phosphate ) is smooth and diy white. It grows in alkaline urine. Proteus being urea splitting organism splits urea to give ammonia and co2 which makes urine alkaline and promotes stag horn calculus ref : - Bailey and Love 27th edition ,chapter 76 , pg no 1406