Let f : A → B is a function defined by f(x) = 2x/(1+x²). If the function f(x) is a bijective function, than the correct statement can be
A. A = B = [−1, 1]
B. A = B = [−2, 2]
C. A = [−1, 1], B =[−2, 2]
D. A = [−2, 2], B = [−1, 1]