In the long run, perfectly competitive firms cannot earn an economic profit

Archibald's Tattoos is a perfectly competitive firm. The firm's costs are shown in the table above. What is Archibald's shut-down point?

A) $10.00 B) $16.67 C) $15.00 D) $12.50

In the prisoner's dilemma game:

A. there is a dominant strategy for a player depending on what the other player does. B. there is a dominant strategy for only one player. C. there is a dominant strategy for both players. D. there is no dominant strategy for either player.