The Sales $S$ (In Thousands of Units) of a Cleaning Solution After

Multiple Choice

The sales $S$ (in thousands of units) of a cleaning solution after $x$ hundred dollars is spent on advertising are given by $S = 20 \left( 1 - e ^ { k x } \right)$ . When $\$ 450$ is spent on advertising, 2500 units are sold. Complete the model by solving for $k$ and use the model to estimate the number of units that will be sold if advertising expenditures are raised to $\$ 650$ . Round your answer to the nearest unit.

A) 3508 units
B) 6401 units
C) 5508 units
D) 2483 units
E) 8787 units