This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharmacokinetics, Subject name: Pharmacology
Clearance- 
Select and explain. 
A. Refers to the efficacy of elimination of a drug by an organ or whole body, B. Cannot be greater than blood flow to an organ, C. Determines the steady of the drug concentration, D. All the above
D: All the above
Answer: D: All the above 
Explanation: Ans. is 'd' i.e., All of the above o Clearance of a drug is the theoretical volume of plasma from which the drug is completely removed in unit time,o It refers to efficacy of elimination of a drug:Clearance =Rate of eliminationPlasma concentrationo As drug is to be removed from plasma in unit time, clearance can not be greater than blood flow to an organ.o Steady state plasma concentration is determined by t 1/2 . t 1/2 is dependent on clearance :154=0-693 xVCLSo, clearance determines the steady state plasma concentration.