A spool of mass $\mathrm{M}$ and radius $2\mathrm{R}$ lies on an inclined plane as shown in figure. A light thread is wound around the connecting tube of the spool and its free end carries a weight of mass $\mathrm{m}$. The value of $\mathrm{m}$ so that system is in equilibrium is

• Correct answer
  A

  $2\mathrm{Msin\alpha }$
• B

  $\mathrm{}\mathrm{Msin\alpha }$
• C

  $2\mathrm{Mtan\alpha }$
• D

  $\mathrm{}\mathrm{Mcos\alpha }$

Hence, the correct answer is option: 'A'.