This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Pharmacology
Calcium carbonate is used for 
Select and explain. 
A. Antacid, B. Renal stone, C. Metabolic alkalosis, D. Renal failure
A: Antacid
Answer: A: Antacid 
Explanation: Ref: Katzung's, 14th ed. pg. 1089* This medication is used to treat symptoms caused by too much stomach acid such as heartburn, upset stomach, or indigestion.* It is an antacid that works by lowering the amount of acid in the stomach.* It can also be used in renal osteodystrophy with hyperphosphatemia, hypocalcemia and osteoporosis like conditions.* It can cause metabolic alkalosis (Milk-alkali syndrome)