Suppose the cost function for a company is given by the following equation, where x is the number of units of phone chargers and y is the number of units of phone covers produced. Complete parts (a) and (b) below. C(x,y) =640x + 70y +4400 (a) In C(x,y), what does 4400 represent? O A. 4400 represents the marginal cost of producing one more phone cover when the number of phone chargers is held constant OB. 4400 represents the marginal cost of producing one more phone charger when the number of phone covers is held constant. c. 4400 represents the fixed costs, or the cost when no items have been produced. O D. 4400 represents the fixed cost, or the cost when 4400 phone chargers and phone covers have been produced. ac ac (b) Find - and ay . What do these quantities represent? ac ac What does represent? A. It represents the marginal cost of producing 1 unit of chargers and 1 unit of covers when both are held constant. B. It represents the marginal cost of producing 1 unit of chargers when the production of covers remains constant. O C. It represents the fixed costs, or the cost when no items have been produced. O D. It represents the marginal cost of producing 1 unit of covers when the production of chargers remains constant. ac av