The drug concentration in the bloodstream t hours after injection is given approximately by C(t) = 4.35et, 0sts 5, where C(t) is the concentration in milligrams per milliliter. (A) What is the rate of change of concentration after 1 hour? After 4 hours? (B) Graph C. (A) Select the correct choice below and fill in the answer box to complete your choice. (Type an integer or a decimal. Do not round until the final answer. Then round to the nearest hundredth as needed.) A. After 1 hour, the concentration is decreasing at the rate of mg/ml per hour. O B. After 1 hour, the concentration is increasing at the rate of mg/ml per hour. O C. After 1 hour, the rate is neither increasing nor decreasing