A wire of length $\ell$ is bent to form a circular coil of some turns. A current $i$ flows through the coil and is placed in a uniform magnetic field $B$. The maximum torque on the coil can be

Question

$\begin {array} {1 1} (a)\;\large\frac{iB\ell^2}{4 \pi} & \quad (b)\;\large\frac{iB\ell^2}{2 \pi} \\ (c)\;\large\frac{iB\ell^2}{ \pi} & \quad (d)\;\large\frac{2iB\ell^2}{4 \pi} \end {array}$