If f'(x) = 4/(1 + t²) and f(1) = 0, Find the antiderivative f(x) that satisfies the given condition?
a) f(x) = arctan(x) + C
b) f(x) = 2 * arctan(x) + C
c) f(x) = 4 * arctan(x) + C
d) f(x) = (4/3) * arctan(x) + C