$[1$ point$]$ Let $f(t)=15e^{1\mathrm{.}3t}$ give the rate of growth of a population $($measured in people per year$)$ as a function of $t,$ the number of years that have passed.

Which of the following expressions would tell you how much the population grew over the first two years?

A$)f(2)=15e^{1\mathrm{.}3(2)}$

B$){\displaystyle \underset{0}{\overset{2}{}}}15e^{1\mathrm{.}3t}dt$

C$)f^{\text{'}}(2)=15e^{13(2)}*(1\mathrm{.}3)$