A drug is infused intravenously (IV) for treatment of a particular disease. The infusion rate of the drug is k0=150mg/hr. The volume of the body fluid V=15 liters. The drug is excreted (removed) through the kidneys at rate ke=0.3/hr, proportional to the concentration of the drug in the body fluids. The drug is ineffective and not used by the body if its concentration is below Cmin=5mg/l and it is metabolized at a rate km=0.2/hr as the concentration is Cmin. a. Write a differential equation in which the infusion rate is the input signal, and the drug concentration is the output signal. b. How long it would take to reach into the minimum concentration level (Cmin) if there would be no excretion? c. How long it would take to reach into the minimum concentration level (Cmin) if there is excretion through the kidneys? d. What will be the maximum concentration of the drug in the body in the steady state