Table 11 -Refer to Table 1

Table 1.1
$$\begin{array}{l}\text { Table } 1.1\\\begin{array} { | l | l | } \hline \text { Hours } & \text { Revenue } \\\hline 1 & 10 \\\hline 2 & 20 \\\hline 3 & 30 \\\hline 4 & 40 \\\hline 5 & 50 \\\hline\end{array}\end{array}$$
-Refer to Table 1.1. What is Sergio's marginal benefit if he tutors for three hours instead of two hours?

A) $50
B) $40
C) $30
D) $20
E) $10