Let u(t) be a continuously differentiable function taking non-negative values for t> 0 and satisfying u'(t) = 4u (t); u(0) = 0. then (a) u(t) = 0 (b) u(t) = t 0

Let u(t) be a continuously differentiable function taking non-negative values for t> 0 and satisfying u'(t) = 4u (t); u(0) = 0. Then (A) u(t) = 0 (B) u(t) = t 0 for 0