Answer is (D) ϕ(an empty set)
Given:
f(x) = |x - π|. (e|x| - )sin|x|
According to the given options, we have to check only at x = 0 and at x = π.
Therefore, it is differentiable at x = 0.
Therefore, it is differentiable at x = π. Hence, the set S is equal to ϕ(an empty set).