In a perfectly competitive market in which all firms are maximizing their economic profits, the demand and supply curves intersect at a price of $10. From this, we know that each
O A. firm's marginal cost of producing the good is $10.
O B. firm is earning positive economic profits at a price of $10 or more.
O C. firm's average variable cost of producing the good is $10.
OD. firm's average total cost of producing the good is $10.