A system has a block G1(s) which has input x (s) and output y1(s). This output is fed as input to a second block G2(s) which has output y2(s). For this system, G1(s) = \(\frac{s^{-1}}{1 + 2s^{-1} + s^{-2}}\).G2(s) for the given system to be invertible is given by _______________

• A. \(\frac{s}{1+2s+s^2}\)
• B. \(\frac{1+2s+s^2}{s}\)
• C. \(\frac{1}{1+2s+s^2}\)
• D. 1+2s+s2