
Remember that in Phase I of solving a nonstandard problem, the indicator row is NOT the bottom (objective) row. Instead, step NS3 demands that we look for the most negative rightside number above the objective row. In our current problem, there is a tie for mostnegative rightside number. It does not matter which "12" we pick, here, but your professor chose the "12" in row 3. If we had chosen the other "12", SIMPLEX METHOD would have still led us to a correct solution. 
