In Applying the High-Low Method What Is the Unit Variable

In applying the high-low method what is the unit variable cost? $\begin{array}{lcr}\text { Month } & \text { Miles } & \text { Total Cost } \\\hline \text { January } & 80,000 & \$ 192,000 \\\text { February } & 50,000 & 160,000 \\\text { March } & 70,000 & 188,000 \\\text { April } & 90,000 & 260,000\end{array}$

A) $2.88
B) $2.50
C) $3.20
D) Cannot be determined from the information given.