If the lines $\frac{1-x}{3}=\frac{2 y-4}{4 K}=\frac{z-3}{2}$ and $\frac{x-1}{3 K}=\frac{1-y}{-1}=\frac{6-z}{5}$ are perpendicular, then the value of K is:

$\frac{10}{7}$ $\frac{7}{10}$ $-\frac{7}{10}$ $-\frac{10}{7}$

$-\frac{10}{7}$

The correct answer is Option (4) → $-\frac{10}{7}$