Refer to the Information Provided in Table 19 -Related to the Economics in Practice on Page 393: Refer

Refer to the information provided in Table 19.8 below to answer the question(s) that follow.
Table 19.8
$$\begin{array} { | c | c | } \hline \text { Total Income } & \text { Total Taxes } \\\hline \$ 20,000 & \$ 2,000 \\\hline 40,000 & 4,800 \\\hline 60,000 & 9,000 \\\hline 80,000 & 16,000 \\\hline\end{array}$$
-Related to the Economics in Practice on page 393: Refer to Table 19.8. If income increases from $60,000 to $80,000, the marginal tax rate is

A) 5%.
B) 20%.
C) 35%.
D) indeterminate from this information.