Correct answer is B.
Given that the f(x) = |log|x|| where

We can see that function is continuous for all x. Now, checking the points of non differentiability.
LHD at x = 1,

∵ LHD ≠ RHD
So, function is not differentiable at x =1.
LHD at x = -1,

∵ LHD ≠ RHD
So, function is not differentiable at x = -1.
At x = 0 function is not defined.
∴ Function is not differential at x = 0 and ±1.