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
Type of injury in which there is brief temporary physiological paralysis of function without organic structural damage is: 
Select and explain. 
A. Concussion., B. Contusion., C. Laceration., D. None.
A: Concussion.
Answer: A: Concussion. 
Explanation: None