S1 and S2 are two DT systems which are connected together to form a new system. Consider the following statements:i) If S1 and S2 are non-causal, then S is non-causalii) If S1 and/or S2 are unstable, then S is unstableThe correct statement from the above is ____________

• A. Both i and ii
• B. Only i
• C. Only ii
• D. Neither i nor ii