A discrete system is represented by the difference equation\(\left[ {\begin{array}{*{20}{c}}{{X_1}\left( {k + 1} \right)}\\{{X_2}\left( {k + 1} \right)}\end{array}} \right] = \left[ {\begin{array}{*{20}{c}}a&{a - 1}\\{a + 1}&a\end{array}} \right]\left[ {\begin{array}{*{20}{c}}{{X_1}\left( k \right)}\\{{X_2}\left( k \right)}\end{array}} \right]\)It has initial conditions X1(0) = 1; X2(0) = 0. The pole locations of the system for a = 1, are

• A. 1 ± j0
• B. -1 ± j0
• C. ±1 + j0
• D. 0 ± j1