The Following Is a Frequency Distribution of the Monthly Expenditures

The following is a frequency distribution of the monthly expenditures for gasoline of 400 households in Chattanooga. $\begin{array}{|c|c|r|}\hline\text { Class } & \text { Expenditure \$) } & \text { \# of households } \\\hline 1 & 0 \text { and under } 20 & 84 \\\hline 2 & 20 \text { and under 40 } & 128 \\\hline 3 & 40 \text { and under } 60 & 68 \\\hline 4 & 60 \text { and under } 80 & 56 \\\hline 5 & 80 \text { and under } 100 & 40 \\\hline 6 & 100 \text { and over } & 24\\\hline\end{array}$ What is the cumulative relative frequency of the 3rd class?

A) .17
B) .53
C) .66
D) .70