The unit step response of a system is t2e-2t. The system function is H(s) is
1
\(\frac{2}{{{s^2}\left( {s + 2} \right)}}\)
2
\(\frac{{2s}}{{{{\left( {s + 2} \right)}^2}}}\)
3
\(\frac{2}{{{{\left( {s + 2} \right)}^3}}}\)
4
\(\frac{{2s}}{{{{\left( {s + 2} \right)}^3}}}\)