Given $A=\left[\begin{array}{ll}1 & 0 \\ 0 & 1\end{array}\right]$, the state transition matrix $e^{A t}$ is given by
- $\left[\begin{array}{cc}0 & e^{-t} \\ e^{-t} & 0\end{array}\right]$
- $\left[\begin{array}{cc}e^{t} & 0 \\ 0 & e^{t}\end{array}\right]$
- $\left[\begin{array}{cc}e^{-t} & 0 \\ 0 & e^{-t}\end{array}\right]$
- $\left[\begin{array}{cc}0 & e^{t} \\ e^{t} & 0\end{array}\right]$