(A) If \(f\) is continuous on \([a, b]\), then \(\int_a^b f(x) dx = \int_a^b x f(x) dx\)

(B) \(\int_0^3 e^{x^2} dx = \int_0^5 e^{x^2} dx + \int_5^3 e^{x^2} dx\)

(C) If \(f\) is continuous on \([a, b]\), then \(\frac{d}{dx}\left(\int_a^b f(x) dx\right) = f(x)\)

(D) Both (1) and (2)