Portman Company's Activity for the First Three Months of 2016

Portman Company's activity for the first three months of 2016 are as follows: $\begin{array}{lll}&\text { Machine Hours}&\text { Electrical Cost }\\\hline\text { January } & 2,100 & \$ 4,800 \\\text { February } & 2,600 & \$ 5,800 \\\text { March } & 2,900 & \$ 6,400\end{array}$ Using the high-low method, how much is the cost per machine hour?

A) $2.00
B) $3.00
C) $2.26
D) $1.78