The roots of the characteristic equations of several systems are given below. Determine in each case if the set of roots represents stable, marginally stable, or unstable systems.S1: -1, -2; S2: -6, -4, 7 and S3: -2, -2 - j3, -2 + j3

• A. S1: marginally stable S2: unstable and S3: unstable
• B. S1: stable S2: marginally stable and S3: unstable
• C. S1: marginally stable S2: stable and S3: unstable
• D. S1: stable S2: unstable and S3: marginally stable