This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Medical, surgical and gynaecological illness complicating pregnancy, Subject name: Gynaecology & Obstetrics
[{'content': 'First sign of magnesium sulphate toxicity is \nSelect and explain. \nA. Loss of deep tendon reflexes, B. Cardiac arrest, C. Respiory depression, D. Decreased urinary output', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Magnesium sulfate toxicity : Loss of deep tendon reflexes. - >7 mEq/L Respiratory depression more than 10 meq/L Cardiac arrest more than 25mEq/L Ref: Dutta Obs 9e pg 222.', 'role': 'assistant'}]