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 profit of the firm from the sale of the 2nd unit of the good?

A) $9
B) $3
C) $1
D) $5
E) $21