Unit step response of a linear time invariant (LTI) system is given by y(t) = (1 − e−2t) u(t). Assuming zero initial condition, the transfer function of the system is

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