Points: 0 Elimination of ethanol from the blood is known to have zeroth order kinetics. Provided no more ethanol enters the blood, the concentration of ethanol in a person's blood will therefore obey the differential equation dM dt = - Ko, where for a certain adult ko = 0.186 g/liter/hr. Complete parts (a) through (c) below. dM (a) Explain why M(t) can only obey the above differential equation if M> 0 (once M drops to 0, it is usual to assume =0). Choose the correct answer below. dt O A. The differential equation becomes undefined at M(t) = 0. B. The differential equation is negative and at M(t) = 0 there is no ethanol left in the body. O C. The differential equation is positive and at M(t) = 0 there is no ethanol left in the body. O D. M(t) = 0 does not exist. (b) If a person's blood alcohol concentration is 2.1 g/liter at midnight, what will his or her blood alcohol concentration be at 7 AM? You may assume that he or she drinks no more alcohol after midnight. His or her blood alcohol concentration will be at 7 AM. (Type an integer or decimal rounded to three decimal places as needed.)