<div>Derive an expression for the force per unit length between two infinitely long straight paralle

Question

$\begin{array}{1 1} (a)\;F= \frac{\mu_0I_1I_2}{r}\\ (b)\;F= \frac{\mu_0I_1I_2}{2 \pi r} \\ (c)\;F= \frac{\mu_0I_1I_2}{r^2} \\ (d)\;F= \frac{\mu_0I_1I_2}{4 \pi r^2} \end{array}$