A bar magnet having a magnetic moment of `2xx10^4jt^(-1)` is free to rotate in a horizontal plane. A horizontal magnetic field `B=6xx10^(-4)` Tesla exists in the space. The work done in taking the magnet slowly from a direction parallel to the field to a direction `60^0` from the field is
Options:
(a) 0.6 J
(b) 12 J
(c) 6 J
(d) 2 J