Ans: B
Let $u=\dfrac{k\sqrt{v}}{w}$, where $k\neq 0$.
I is true.
$\begin{array}{rcl}
u & = & \dfrac{k\sqrt{v}}{w} \\
u^2 & = & \left( \dfrac{k\sqrt{v}}{w} \right)^2 \\
u^2 & = & \dfrac{k^2 v}{w^2} \text{, where $k^2 \neq 0$.}
\end{array}$
II is not true.
$\begin{array}{rcl}
u & = & \dfrac{k\sqrt{v}}{w} \\
u^2 & = & \left( \dfrac{k\sqrt{v}}{w} \right)^2 \\
u^2 & = & \dfrac{k^2 v}{w^2} \\
v & = & \dfrac{1}{k^2} u^2 w^2 \text{, where $k^2 \neq 0$.}
\end{array}$
III is true.
$\begin{array}{rcl}
u & = & \dfrac{k\sqrt{v}}{w} \\
w & = & \dfrac{k\sqrt{v}}{u} \text{, where $k \neq 0$.}
\end{array}$
