A system is said to be locally stable if:

• A. The region S (e) is small
• B. There exist a real number >0 such that || x (t0) || <=r
• C. Every initial state x (t0) results in x (t) tends to zero as t tends to infinity
• D. They are unstable
• E. is smallb) There exist a real number >0 such that || x (t0) || <=rc) Every initial state x (t0) results in x (t) tends to zero as t tends to infinityd) They are unstable