This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology and Reproduction, Subject name: Physiology
[{'content': 'In tetany hyperexcitability is due to: \nSelect and explain. \nA. Low Ca++ causes | permeability to Na+, B. Prevent k+ release, C. Prevent Na+ & K+ release, D. |Ca++ produce generation of AP', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Low Ca++ causes | permeability to Na+(Ref: Ganong, 25th ed/p.380)Reason for hyperexcitability in tetany - low serum calcium levels moves more sodium ions entry into the cell leading to more frequent action potential generation', 'role': 'assistant'}]