(Solved): For the given matrices, complete parts (a) and (b) below. \[ A=\left[\begin{array}{rrr} 4 & 3 & 1 ...

For the given matrices, complete parts (a) and (b) below. \[ A=\left[\begin{array}{rrr} 4 & 3 & 1 \\ 3 & 2 & -1 \\ 4 & 10 & 1 \end{array}\right] \quad B=\left[\begin{array}{rrr} 12 & 7 & -5 \\ -7 & 0 & 7 \\ 22 & -28 & -1 \end{array}\right] \] a. Compute \( A B \) and \( B A \). Select the correct choice below and, if necessary, fill in the answer box to complete your choice. A. \( \mathrm{AB}= \) (Type an integer or simplified fraction for each matrix element.) B. The matrix \( A B \) does not exist.