Two blocks of mass M₁ and M₂ are connected with a string passing over a pulley as shown in fig.

The block M₁ lies on a horizontal surface. The coefficient of fiction between the block M and the horizontal surface is µ. The system  accelerates. What additional mass m so that the system does not accelerate ?

• A

  $\frac{{\mathrm{M}}_2-{\mathrm{M}}_1}{\mathrm{\mu }}$

• B

  $\frac{{\mathrm{M}}_2}{\mathrm{\mu }}-{\mathrm{M}}_1$

• C

  ${\mathrm{M}}_2-\frac{{\mathrm{M}}_1}{\mathrm{\mu }}$

• D

  $\left({\mathrm{M}}_2-{\mathrm{M}}_1\right)\mathrm{\mu }$