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: Physiology
Salivary amylase is activated by 
Select and explain. 
A. Na+, B. K+, C. HCO3-, D. Cl-
D: Cl-
Answer: D: Cl- 
Explanation: Both salivary and pancreatic α -amylases are activated by Cl–