This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
About first order kinetics,true statement is 
Select and explain. 
A. Clearance remains constant, B. Fixed amount of drug is eliminated, C. Half life increases with dose, D. Decreases clearance with increased dose
A: Clearance remains constant
Answer: A: Clearance remains constant 
Explanation: Clearance is variable in zero-order kinetics because a constant amount of the drug is eliminated per unit time, but it is constant in first-order kinetics, because the amount of drug eliminated per unit time changes with the concentration of drug in the blood Ref-KDT 6/e p32