The Sales of a Product S (In Thousands of Dollars)

Multiple Choice

The sales of a product S (in thousands of dollars) are given by , where x is the advertising expenditure (in thousands of dollars) . Find the rate of change of sales with respect to advertising expenditure. Use the second derivative to find how this rate is changing at . Round your answer to two decimal places. ​

A) 0.89
B) -0.03
C) 0.00
D) -0.89
E) -0.02