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
A patient on lithium therapy was found to be hypertensive also. Which of the following antihypertensive drugs is contraindicated in a patient on lithium therapy in order to prevent toxicity ? 
Select and explain. 
A. Clonidine, B. Beta blockers, C. Calcium channel blockers, D. Diuretics
D: Diuretics
Answer: D: Diuretics 
Explanation: None