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
Which of the following would make the most sense as a more specific diagnostic test of shock? 
Select and explain. 
A. A CSF (spinal) tap to check for meningitis., B. A brainstem auditory evoked response test to see if the person can hear ok., C. A pupillary light reflex test to check how well the eyes are working., D. The measurement of serum lactate, elevated levels of which are an indicator of shock.
D: The measurement of serum lactate, elevated levels of which are an indicator of shock.
Answer: D: The measurement of serum lactate, elevated levels of which are an indicator of shock. 
Explanation: D: Serum lactate is one of the enzymes that can indicate the occurrence of shock.
A: Checking for meningitis is different from the identification cardiogenic shock.
B: Auditory sense have nothing to do with shock.
C: The eyes could not determine the diagnosis of cardiogenic shock