On a smooth inclined plane, a body of mass m is attached between two massless springs. The other ends of the springs are fixed to firm supports. If each spring has force constant k, the period of oscillation of the body is:
 

• A

  $2\mathrm{\pi }\sqrt{\frac{\mathrm{m}}{2\mathrm{k}}}$

• B

  $2\mathrm{\pi }\sqrt{\frac{2\mathrm{m}}{\mathrm{k}}}$

• C

  $2\mathrm{\pi }\sqrt{\frac{\mathrm{mg} \sin \mathrm{\theta }}{2\mathrm{k}}}$

• D

  $2\mathrm{\pi }\sqrt{\frac{2\mathrm{mg} \sin \mathrm{\theta }}{\mathrm{k}}}$