If $A$ and $B$ are invertible matrices, then which of the following is not correct ? (A) $(A + B)^{-1} = B^{-1} + A^{-1}$ (B) $(AB)^{-1} = B^{-1}A^{-1}$ (C) $\text{adj } (A) = | A | A^{-1}$ (D) $| A |^{-1} = | A^{-1} |$