The sales in thousands of a new type of product are given by S(t) = 130 - 702 0\"\

The sales in thousands of a new type of product are given by S(t) = 130 - 70e - 0.4t , where t represents time in years. Find the rate of change of sales at the time when t = 7. Round to the nearest tenth. O O A. - 1.7 thousand per year 1.7 thousand per year C. -460.5 thousand per year 460.5 thousand per year