Let $A = \left[ a_{ij} \right]$ be a square matrix of order 2 with entries either 0 or 1. Let $E$ be the event that $A$ is an invertible matrix. Then the probability $\mathrm{P}(\mathrm{E})$ is:\\
(1) $\frac{3}{16}$\\
(2) $\frac{5}{8}$\\
(3) $\frac{3}{8}$\\
(4) $\frac{1}{8}$