What Is the Marginal Net Benefit of Producing the Twentieth

Multiple Choice

What is the marginal net benefit of producing the twentieth unit?

$\begin{array} { c c c } \text { No. Units Produced } & \text { Total Revenue } & \text {Total Costs } \\ 0 & 0 & 0 \\ 10 & 120 & 40 \\ 20 & 200 & 100 \\ 30 & 270 & 170 \\ 40 & 310 & 260 \\ 50 & 330 & 370 \\\end{array}$

A) 2
B) -5
C) -2
D) 8