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: Forensic Medicine
Primary impact injury to brain: DNB 10 
Select and explain. 
A. Concussion, B. Cerebral edema, C. Hypoxic injury, D. Intracerebral hematoma
A: Concussion
Answer: A: Concussion 
Explanation: Ans. Concussion