Total Revenue Is in Dollars and X Is the Number

Multiple Choice

Total revenue is in dollars and x is the number of units. Suppose that the total revenue function for a commodity is Find the marginal revenue at and tell what it predicts about the sale of the next unit. Round your answer to two decimal places. ​

A) 13.80. The selling of the next unit increases revenue by $13.80.
B) 12.60. The selling of the next unit increases revenue by $12.60.
C) -414.00. The selling of the next unit decreases revenue by $414.
D) -30.00. The selling of the next unit decreases revenue by $30.
E) -15.00. The selling of the next unit decreases revenue by $15.