This method is based on opportunity loss, also called regret. It is defined as the difference between the optimal and the actual pay-off. Regret is the amount lost when the best alternative is not selected.
This method proposed that maximum regret be minimized by choosing the best pay off for each event. The regret of each event for each alternative is calculated and regret matrix or opportunity loss table is created. This table shows the losses to be incurred if the alternative is not selected for the best outcomes of each event.
If the objective is maximization, the maximum value of each event is determined. All values of the relevant event are subtracted from this maximum value. If the objective is minimization, the minimum value of each event is determined. The smallest value of each event is subtracted from all values of relevant event. In this way, the regret matrix is obtained.
After the regret matrix has been constructed, the maximum opportunity loss (regret) for each alternative is located. Then the alternative with the smallest value
among these maximum regrets selected.

In this method, regardless of the objective function, the smallest value is always selected from the regret matrix.

According to these information, the correct answer is given in the option C.