This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gastrointestinal tract, Subject name: Pharmacology
[{'content': 'Which one of the following is not an antacid? \nSelect and explain. \nA. Magnesium sulfate, B. Magaldrate, C. Magnesium carbonate, D. Magnesium phosphate', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Clasification of antacids 1.systemic( sodium carbonate,sodium citrate) 2.Non systemic(magaldrate,magnesium carbonate,magnesium phosphate,magnesium hydroxide,aluminium hydroxide,calcium carbonate) ESSENTIALS MEDICAL PHARMACOLOGY SIXTH EDITION KD TRIPATHI PG NO.626', 'role': 'assistant'}]