A.
the zeros are at z=0 and z=-1; the poles are at ; the system is unstalbe.
B.
the zeros are at z=1 and z=-1; the poles are at ; the system is stalbe.
C.
the zeros are at z=0 and z=1; the poles are at ; the system is stalbe.
D.
the zeros are at z=0 and z=-1; the poles are at ; the system is unstalbe.