If transfer function of a system is H(z) = 6 + z-1 + z-2 then system is

If transfer function of a system is H(z) = 6 + z^-1 + z^-2 then system is

Answer: Option A

Explanation:

H(z) = 6 + z^-1 - z^-2, solve it by considering H(z) = 0 z = 1/3, -1/2 in H(z) only numerator.

Hence z = 1/3, - 1/2 will be zero, and if zero lies inside the unit circle, system will be of minimum phase.