Which of the following best represents the variation of magnetic induction (B) with distance (r) from a long straight current-carrying wire?

Representation of the variation of magnetic induction (B) with distance (r) from a long straight current-carrying wire is

Magnetic field due to a straight current-carrying conductor: Biot-Savart Law

Magnetic field (B) at a radial distance (r), due to a wire-carrying current is given by:

$B=\frac{{\mu }_{\circ }I}{2\pi r}$ Where ${\mu }_{\circ }$ is the permeability of free space $\left(4\pi \times {10}^{-7}\mathrm{Tm}/\mathrm{A}\right)$, and (I) is the current intensity. 

Magnetic field intensity, $B=\frac{{\mu }_{\circ }I}{2\pi r}$

$\Rightarrow B\times \frac{1}{r}$Thus, the magnetic field is inversely proportional to the distance from the current-carrying wire. which shows the relation of y= 1/x graph 

So we can observe in this graph