Ans: D
Since the two straight lines are perpendicular to each other, then the product of the slopes of the straight lines is equal to $-1$.
Since the two straight lines are perpendicular to each other, then the product of the slopes of the straight lines is equal to $-1$.
$\begin{array}{rcl}
\dfrac{-h}{k} \times \dfrac{-4}{3} & = & -1 \\
4h & = & -3k \ \ldots \unicode{x2460}
\end{array}$
Since the two straight lines intersect at a point on the $x$-axis, then the $x$-intercepts of the straight lines is equal.
$\begin{array}{rcl}
\dfrac{-15}{h} & = & \dfrac{5}{4} \\
h & = & -12
\end{array}$
Sub. $h=-12$ into $\unicode{x2460}$, we have
$\begin{array}{rcl}
4(-12) & = & -3k \\
k & = & 16
\end{array}$
