The Following Four Months of Data Were Collected on Utility

The following four months of data were collected on utility cost and the number of labour hours in Edmonton Company's factory.
$\begin{array}{lrr}& \text { Utility } & \text { Labour } \\\text { Month } & \text { cost } & \text { hours }\\\text { May } & \$ 22,100 & 3,975 \\\text { June } & 24,600 & 5,430 \\\text { July } & 23,500 & 4,400 \\\text { August } & 20,140 & 3,200\end{array}$
-Refer to the Figure.What is the variable rate for the utility cost when using the high-low method?

A) $1.02
B) $1.07
C) $2.00
D) $2.80