The Sales of a Mature Product (One Which Has Passed $\mathrm{S}(\mathrm{t})=\mathrm{S}_{\mathrm{O}} \mathrm{e}^{- \text {at }}$

Multiple Choice

The sales of a mature product (one which has passed its peak) will decline according to the function $\mathrm{S}(\mathrm{t}) =\mathrm{S}_{\mathrm{O}} \mathrm{e}^{- \text {at }}$ , where $\mathrm{t}$ is time in years since the peak sales. Find the sales of a product 22 years after its peak sales if $\mathrm{a}=0.13$ and $\mathrm{So}=15,100$ .

A) 17,196
B) 865
C) 300,274
D) 433