A function f: R → R satisfies the equation f(x + y) = f(x).f(y) for all x, y ∈ R; f(x) ≠ 0. Suppose that the function f(x) is differentiable at x = 0 and f'(0) = 2. If f'(x) = λ. f(x), then the value of λ is
1
1
2
2
3
\(\frac{1}{2}\)
4
Any real number