Two parallel connecting wires placed at a distance d apart carry equal currents in the same direction then the intensity of the magnetic field at a point between them will be

Question

$\begin {array} {1 1} (a)\;\large\frac{\mu_0i}{2 \pi d} & \quad (b)\;\large\frac{\mu_0i}{ \pi d} \\ (c)\;\large\frac{\mu_0i}{ \pi d^2} & \quad (d)\;Zero \end {array}$