The Figure Given Below Shows the Revenue and Cost Curves

Multiple Choice

The figure given below shows the revenue and cost curves of a perfectly competitive firm.Figure 10.1

-Suppose a perfectly competitive firm's total revenue is equal to $210 and its output is 70 units, when its marginal-cost curve intersects the marginal-revenue curve. What is the marginal revenue earned by the firm?

A) $15
B) $3
C) $30
D) $7
E) $70