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: Medicine
A paient after vomiting several times develops carpopedal spasm. The most approriate treatment would - 
Select and explain. 
A. Intravenous injection of 20 ml 10% calcium gluconate solution, B. Intravenous infusion of isotonic saline, C. Oral ammonium chloride 2mg four times a day, D. 5% CO2inhalation
A: Intravenous injection of 20 ml 10% calcium gluconate solution
Answer: A: Intravenous injection of 20 ml 10% calcium gluconate solution 
Explanation: None