Determine the transfer function described by the following difference equation:
\(y\left[ n \right] - \frac{1}{2}y\left[ {n - 1} \right] = 2x\left[ {n - 1} \right]\)1
\(\frac{2}{{z - 0.5}}\)
2
\(\frac{2}{{z + 0.5}}\)
3
\(\frac{{2z}}{{z - 0.5}}\)
4
\(\frac{{2z}}{{z + 0.5}}\)