Answer: We have to find which of the provided functions is not differentiable at x = 0, this means that the slope does not exist at that point, and the derivative when evaluated also does not exist:
The combined plot of the functions:
The plot suggests that the square root must be checked for differentiability at the x = 0, therefore:

Therefore the derivative does not exist for the square root function at the x = 0, the answer is, Option(B).