A short bar magnet is arranged with its North pole pointing geographical North. It is found that the horizontal component of Earth's magnetic induction ($B_H$) is balanced by the magnetic induction of the magnet at a point which is at a distance of 20 cm from its center . The magnetic moment of the magnet is : $( If \: B_H = 4 \times 10^{-5}\: Wb\: m^{-2})$:

Question

$\begin {array} {1 1} (1)\;3.2\: A-m^2 & \quad (2)\;1.6\: A-m^2 \\ (3)\;6.4\: A-m^2 & \quad (4)\;0.8\: A-m^2 \end {array}$