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: Pharmacology
Therapeutic drug monitoring is required for: 
Select and explain. 
A. Prodrugs, B. Levodopa, C. Lithium carbonate, D. MAO inhibitors
C: Lithium carbonate
Answer: C: Lithium carbonate 
Explanation: None