The z transform of the discrete signal x(n) = an u(n) is

• A. \(\frac{z}{{z - a}}\) for all z
• B. \(\frac{z}{{z - a}}\) for all |z| ≠ |a|
• C. \(\frac{z}{{z - a}}\) for all |z| < |a|
• D. \(\frac{z}{{z - a}}\) for all |z| > |a|