The Following Table Shows the Total Revenue (In Dollars)and Total

Multiple Choice

The following table shows the total revenue (in dollars) and total cost (in dollars) from the production and sale of different units of a product.
Table 2-1

-Refer to Table 2-1.What is the marginal revenue of the firm associated with the sale of the 5th unit of the good?

A) $55
B) $8
C) $7
D) $48
E) $4