Given the function:
[tex]n(t)=n_02^{(\frac{t}{a})}[/tex]To evaluate n(a) we plug in a wherever there is a t. This way,
[tex]\begin{gathered} n(a)=n_02^{(\frac{a}{a})} \\ \rightarrow n(a)=2n_0 \end{gathered}[/tex]This way, we can conlcude that:
[tex]n(a)=2n_0[/tex]Answer: Option C