The sales of a new high-tech item (in thousands) are given by the following function, where t represents time in years. Find the rate of change of sales at each time. S(t) = 101- 100e-0.3t (a) After 1 year. (b) After 5 years. (c) What is happening to the rate of change of sales as time goes on? (d) Does the rate of change of sales ever equal zero? . . . (a) The rate of change after 1 year is thousand items per year. (Round to three decimal places as needed.)