4) Given matrices \( A , B , C \) , and \( D \) defined as shown, choose the true statement.
\( A = \left[ \begin{array} { l l } { 1 } & { 1 } \\ { 1 } & { 1 } \end{array} \right] B = \left[ \begin{array} { l l } { 0 } & { 0 } \\ { 0 } & { 0 } \end{array} \right] C = \left[ \begin{array} { l l } { 0 } & { 1 } \\ { 1 } & { 0 } \end{array} \right] \left[ \begin{array} { l l } { 1 } & { 0 } \\ { 0 } & { 1 } \end{array} \right] \)
A) \( A = A ^ { - 1 } \)
B) \( B = B ^ { - 1 } \)
C) \( C = C ^ { 1 } \)
D) \( D = D ^ { - 1 }\)
