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 psychiatric patient taking medication develops a tremor, thyroid enlargement and leucocytosis. Drug implicated is: 
Select and explain. 
A. Clomipramine, B. Haloperidol, C. Lithium, D. Olanzapine
C: Lithium
Answer: C: Lithium 
Explanation: None