This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General physiology, Subject name: Physiology
Which of the following techniques is used to study the current flow across a single ion channel? 
Select and explain. 
A. Voltage clamp technique, B. Patch clamp technique, C. Iontophoresis, D. Galvanometry
B: Patch clamp technique
Answer: B: Patch clamp technique 
Explanation: Patch clamp technique is a laboratory technique in electrophysiology used to study ionic currents in individual isolated living cells,tissue sections or patches of cells Ref:Guyton and Hall textbook of medical physiology 12th edition,page number:66,67,68