As Tia solved the system of equations below, she transformed matrices at different steps during the process. -a-b+2c=7
2a+b+c=2
-3a+2b+3c=7
She noted the following matrices.

I 1 1 0 | 0, 0 1 0 | -1, 0 0 1 | 3
II -1 -1 2 | 7, 2 1 1 | 2, -3 2 3| 7
III 1 1 -2 | -7, 0 1 -5 | -16, 0 0 22 | 66
IV 1 1 0| -1, 0 1 0 | -1, 0 0 1 | 3

In which order should the matrices be arranged when solving the system from start to finish?
I, IV, III, II
II, III, IV, I
II, IV, I, III
IV, II, III, I