Ans: A
$\begin{array}{rcl}
\dfrac{2}{u} + \dfrac{3}{v} & = & 4 \\
\dfrac{2v+3u}{uv} & = & 4 \\
2v+3u & = & 4uv \\
3u-4uv & = & -2v \\
u(3-4v) & = & -2v \\
u & = & \dfrac{-2v}{3-4v} \\
u & = & \dfrac{2v}{4v-3}
\end{array}$
