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: Medicine
A patient presents to the emergency with altered sensorium. All of these tests should be done except: 
Select and explain. 
A. Complete blood counts, B. Random blood sugar, C. Lumbar puncture, D. Non-contrast CT head
C: Lumbar puncture
Answer: C: Lumbar puncture 
Explanation: Ans: C. Lumbar puncture(Ref Harrison 19/e p1773, 18/e p2251)Recommends imaging study prior to lumbar puncture.Excludes raised 1CP causes (large intracranial mass lesion) a Preventing herniation.