Two identical long conducting wires AOB and COD are placed at right angle to each other, with one above other such that O is their common point for the two. The wires carry `I_1` and `I_2` currents, respectively. Point P is lying at distance d from O along a direction perpendicular to the plane containing the wires. The magnetic field at the point P will be

Options

A. `(mu_0)/(2pid)(I_1/I_2)`
B. `(mu_0)/(2pid) (I_1 + I_2)`
C. `(mu_0)/(2pid) (I_1^2 - I_2^2)`
D. `(mu_0)/(2pid) (I_1^2 + I_1^2)^(1/2)`