If the lines $3x – 4y + 4 = 0$ and $6x – 8y – 7 = 0$ are tangents to a circle, then find the radius of the circle

Question

$\begin{array}{1 1}\large\frac{3}{2}\text{units}\\\large\frac{3}{4}\text{units}\\\large\frac{3}{8}\text{units}\\\large\frac{3}{5}\text{units}\end{array}$