Obtain a state-space realization of the transfer function, G(s) = s²/(s² - 4s) * s/(s² - 1).
a) A = [0, 1; -4, 0], B = [0; 1], C = [1, 0], D = 0
b) A = [0, 1; 4, 0], B = [0; 1], C = [1, 0], D = 0
c) A = [0, 1; 2, 0], B = [0; 1], C = [1, 0], D = 0
d) A = [0, 1; -2, 0], B = [0; 1], C = [1, 0], D = 0