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: Surgery
Which of the following is true regarding local anesthesia? 
Select and explain. 
A. They are basic salts of weak acids, B. Not effective in alkaline pH, C. Form salts with acids, D. They are acidic salts of weak bases
D: They are acidic salts of weak bases
Answer: D: They are acidic salts of weak bases 
Explanation: None