"in game theory, a dominant strategy exists."

Game theory is the study of math and logic behind problems and cooperation. It has logical steps that can be used in making life choices. In game theory, a dominant strategy of Nash equilibrium exist. Nash equilibrium is reach when players choose their own dominant strategy in no unilateral profitable deviation from any other players. In addition, no players would take action as long as other players remain the same. Therefore, Nash equilibrium is self-enforcing strategy. 

answer/// equals both average variable cost and average total cost at their respective minimums;