question: 1 point(s) po The sales in thousands of a new type of product are given by S(t) = 180-50 e-0.31, where t represents time in years. Find the rate of change of sales at the time when t=3. Round to the nearest tenth. OA. 6.1 thousand per year B. -36.9 thousand per year OC. -6.1 thousand per year OD. 36.9 thousand per year