The pole strength of a bar magnet is 48 ampere-metre and the distance between its poles is `25cm`. The moment of the couple by which it can be placed at an angle of `30^(@)` with the uniform magnetic intensity of flux density `0.15 "newton"//"ampere-metre"` will be
A. `12 "newton-metre"`
B. `18 "newton-metre"`
C. `0.9 "newton-metre"`
D. none of these
