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: Pharmacology
Which of the following is not an antacid drug: March 2005 
Select and explain. 
A. Aluminium hydroxide, B. Magnesium sulphate, C. Sodium bicarbonate, D. Calcium carbonate
B: Magnesium sulphate
Answer: B: Magnesium sulphate 
Explanation: Ans. B: Magnesium sulphate Examples of antacids Aluminium hydroxide Magnesium hydroxide, magnesium trisilicate (Phillips' Milk of Magnesia) Aluminum carbonate gel Calcium carbonate Sodium bicarbonate, Sodium citrate Bismuth subsalicylate Magaldrate