Is the following true or false?

(a) If a function f is continuous at x = 0, then the derivative, f'(0) exists. (b) If f is differentiable at 2: =11, then f must be continuous at x = a. (c) If the tangent line to the graph of f at the point (a, f ((1)) has equation 2x +y+ 3 = 0,thenf'(a) = 2