The work done in deflecting a magnet of magnetic moment 'M through al angle ‘$\mathrm{\theta }$' in a field of strength ‘H’ is

• A

  $\mathrm{MH} (1-\mathrm{cos\theta })$

• B

  $\mathrm{MH} (1-\mathrm{sin\theta })$

• C

  $\mathrm{MH} \mathrm{sin\theta }$

• D

  $\mathrm{MH} (1+\mathrm{cos\theta })$