The Table Given Below Shows the Total Revenue and Total

Multiple Choice

The table given below shows the total revenue and total cost of a firm at different levels of output.Table 10.2

-Given a perfectly competitive market structure, at the profit-maximizing output level, a firm's total fixed cost is $10, total variable cost is $100, marginal revenue is $4, and the quantity demanded is 50. The total profit earned by the firm is:

A) $70.
B) $65.
C) $90.
D) $75.