Minimum value of coefficient of friction

[Jahnavi]

Homework Statement

Ans: c)

Homework Equations

The Attempt at a Solution

I can solve this problem if only I understand the setup . I am sure the diagram is missing something .

Can someone help me understand the problem statement in context of the setup ?

 

[Orodruin]

It looks to me that the diagram is missing a string. Probably from the lower pulley to the block with mass 2m, but I did not check that this leads to the given answer.

 

[haruspex]

I did not check that this leads to the given answer

It does.

 

[Jahnavi]

Thanks both of you .