(4 pts; no partial credit). Suppose that f(r) = ru(), where u(r) is a differentiable function at r = 2 such that u(2) = 3, u'(2) - 1. Find f'(2). (a) 1.5 + In 2 (b) 12 + 8 In 2 (C) 12 (d) 8 In 2 (e) 2