This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Pharmacology
False statement regarding Lithium is 
Select and explain. 
A. Maximum plasma concentration is avoided due to low therapeutic index, B. Contraindicated in pregnancy, C. No individual variation in the rate of excretion, D. 80% Reabsorbed in the proximal convoluted tubule
C: No individual variation in the rate of excretion
Answer: C: No individual variation in the rate of excretion 
Explanation: (No individuals variation in the rate of excretion) (416-KDT) (389-BB) (435-KDT 6th)LITHIUM - is well absorbed orally and is neither protein bound nor metabolized*** High peak plasma concentrations are avoided by using sustained-release formulations which deliver the peak plasma lithium concentration in about 5 hour (389-BB).* Only the kidneys eliminate lithium. Like sodium, it is filtered by the Glomerulus and 80% is reabsorbed by the proximal tubule but it is not reabsorbed by the distal tubule (389-BB).* **There is marked individual variation in the rate of lithium excretion. Thus with the same daily dose, different individuals attain widely different plasma concentration. Since the margin of safety is narrow, monitoring serum lithium is essential for optimum therapy** * Lithium is contraindicated during pregnancy, and sick sinus syndrome.