The magnetic field existing in a region is given by $\vec{B}=B_{0}\left[1+\frac{x}{l}\right]$
A square loop of edge $l$ and carrying current $I$ is placed with its edges parallel to the $x-y$ axis. The magnitude of the net magnetic force experienced by the loop is :
(a) $2 B_{0} n$
(b) $B_{0} I_{0} l$
(c) $B_{0} I l$
(d) $B I l$