If a magnet of length `10cm` and pole strength `40 A-m` is placed at an angle of `45^(@)` in an uniform induction field of intensity `2xx10^(-4)T`, the couple acting on it is
A. `0.5656xx10^(-4)N-m`
B. `0.5656xx10^(-3)N-m`
C. `0.656xx10^(-4)N-m`
D. `0.656xx10^(-5)N-m`