Z transform and its Application on Digital Signal Processing related Questions and Answers

Question :   The z-transform X(z) of the signal x(n)=anu(n) has: 1. One pole at z=0 and one zero at z=a 2. One pole at z=0 and one zero at z=0 3. One pole at z=a and one zero at z=a 4. One pole at z=a and one zero at z=0 Answer :   4 - One pole at z=a and one zero at z=0