This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
[{'content': 'A PATIENT WAS ON LITHIUM THERAPY FOR BIPOLAR DISORDER FOR 6MONTHS SHE KEPT THE FAST FOR FEW DAYS .SHE PRESENTED WITH S3 , COARSE TREMORS , CONFUSION AND WEAKNESS OF LIMBS. WHICH OF THE FOLLOWING SHOULD BE DONE NEXT TO ASSESS HER CONDITION ? \nSelect and explain. \nA. S.ELECTROLYTES, B. ECG, C. MRI, D. S.LITHIUM LEVELS', 'role': 'user'}, {'content': 'Answer: D \nExplanation: REF : KD TRIPATHI 8TH ED', 'role': 'assistant'}]