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: Biochemistry
Elevated levels of serum glutamic oxaloacetic transaminase is indicative of: 
Select and explain. 
A. Deficiency of glutamic acid, B. Deficiency of oxaloacetic acid, C. Liver disease, D. All of the above
C: Liver disease
Answer: C: Liver disease 
Explanation: None