If \(f(x) = \begin{cases} 2a-x & \quad \text{for } -a < x < a \text{}\\ 3x-2a & \quad \text{for } x≥a \text{ } \end{cases}\) then which one of the following is true?
(a) f(x) is not differentiable at x = a
(b) f(x) is discontinuous at x = a
(c) f(x) is continuous for all x in R
(d) f(x) is differentiable for all x ≥ a