If A = [aij] is a square matrix of order 2 such that aij = \(\left\{ \begin{array}{l} 1,when i \ne j\\ 0,when i = j \end{array} \right.\) , then A2 is :
1
\(\left[ {\begin{array}{*{20}{c}} 1&0\\ 1&0 \end{array}} \right]\)
2
\(\left| {\begin{array}{*{20}{c}} 1&1\\ 0&0 \end{array}} \right|\)
3
\(\left| {\begin{array}{*{20}{c}} 1&1\\ 1&0 \end{array}} \right|\)
4
\(\left[ {\begin{array}{*{20}{c}} 1&0\\ 0&1 \end{array}} \right]\)