Consider the $z$-transform $X(z)=5 z^2+4 z^{-1}+3 ; 0<|z|<\infty$. The inverse $z$-transform $x[n]$ is
- $5\; \delta[n+2]+3\; \delta[n]+4\; \delta[n-1]$
- $5\; \delta[n-2]+3\; \delta[n]+4\; \delta[n+1]$
- $5\; u[n+2]+3\; u[n]+4\; u[n-1]$
- $5\; u[n-2]+3\; u[n]+4\; u[n+1]$