This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Local and Regional Anesthesia), Subject name: Anaesthesia
Local anesthetics block which ion channel: 
Select and explain. 
A. K+, B. Ca+, C. Na+, D. Cl
C: Na+
Answer: C: Na+ 
Explanation: Ans (c) Na+Ref: KDT 6th ed. / 353