An infinitely long current carrying wire and a small current carrying loop are in the plane of the paper as shown. The radius of the loop is $$a$$ and distance of its centre from the wire is $$d$$ ($$d \gg a$$). If the loop applies a force $$F$$ on the wire then:

A

$$F \propto \frac{a^2}{d}$$

B

$$F = 0$$

C

$$F \propto \frac{a^2}{d^3}$$

D

$$F \propto \frac{a}{d}$$