<prompt> Volume of plasma from which a substance is completely removed by filterationsecretion in kidney is equal to-Rate of eliminationClearanceVolume of distributionBioavailability  <response>: Ans. is b i.e., Clearance Once a drug is absorbed and distributed among the tissues and body fluids, it is then eliminated mainly by the liver and kidneys. The amount of drug eliminated from the body per unit time is called rate of eliminations. Elimination of a drug from the plasma is quantified in term of its clearance.. Rate of elimination It is the amount of drug eliminated per unit time from the body. Clearance Elimination of a drug from the plasma is quantified in terms of its clearance. The clearance of a drug is the theoretical volume of plasma from which the drug is completely removed in unit time.Clearance CL Rate of elimination---Plasma concentration Renal clearance is the volume of plasma that is totally cleared of a drug in 1 minute during passage throughkidney. Similarly, liver clearance is plasma volume that is totally cleared of a drug in 1 minute during passage through liver. 