In general, an exponential function has the form shown below
[tex]\begin{gathered} f(x)=ab^x \\ a,b\rightarrow\text{ constants} \\ b\rightarrow\text{ growth rate if }b>1 \end{gathered}[/tex]
In our case,
[tex]\begin{gathered} a=3000,b=2 \\ \Rightarrow f(t)=3000(2)^t \end{gathered}[/tex]
Therefore, the answer is 3000(2)^t, the first option.
