Recall lab 6 where a drug is administered every few hours in regular dose sizes, neutralized at an exponential rate with a decay rate constant k hr'l. Not all of the drug is neutralized before the next dose is administered. Denote by A(t) the amount of drug in the patient's system at time t hours. (1 mark) Unrelated to other problems, suppose instead that the closed form of a series expressing the residual amount Rn of a drug left in a patient's system at the end of the n'th dosage period is 68''2[111%1- The eventual W is= O.2 a) 1 6\" b) 2-\"?! 1 c) 25-91 '1) e516\" e) 1682-51 _e- - _