Use the table below to answer the following questions. Table 11.2.1 Short Description: A table shows the total revenue schedule and total cost schedule of a perfectly competitive firm. Long Description: The column headings from left to right are output (units), total revenue (dollars), and total cost (dollars). The row entries are as follows. Row 1. 0, 0, 25. Row 2. 1, 30, 49. Row 3. 2, 60, 69. Row 4. 3, 90, 86. Row 5. 4, 120, 100. Row 6. 5, 150, 116. Row 7. 6, 180, 136. Row 8. 7, 210, 176. Refer to Table 11.2.1, which gives the total revenue schedule and total cost schedule of a perfectly competitive firm. The marginal revenue received from the sale of the 4th unit of output is $30. $3. $10. $15. $120