GATE EC 2015 Set 1 Q24 — Electronic Devices

Consider a straight, infinitely long, current carrying conductor lying on the z-axis. Which one of the following plots (in linear scale) qualitatively represents the dependence of $H_{\phi}$ on $r$, where $H_{\phi}$ is the magnitude of the azimuthal component of magnetic field outside the conductor and $r$ is the radial distance from the conductor?