$\underset{x0}{lim}\frac{1}{2x}{\displaystyle \underset{2x}{\overset{0}{}}}(1tan3t{)}^{\frac{1}{t}}dt=$

$($a$)-e^4$

$($b$)-e^3$

$($c$)0$

$($d$)e^3$

$($e$)e^4$