Based on the Following Cost Data, Items Labeled (A) and (B)

Based on the following cost data, items labeled (a) and (b) in the table below are which of the following amounts, respectively? $$\begin{array} { | l | r | r | } \hline \text { Number of units: } & 1,500 & 3,000 \\\hline \text { Total cost: } & & \\\hline \text { Variable } & \$ 7,500 & \$ 15,000 \\\hline \text { Fixed } & \$ 6,000 & \$ 6,000 \\\hline & & \\\hline \text { Cost per unit: } & & \\\hline \text { Variable } & \$ 5 & \text { (a) } \\\hline \text { Fixed } & \$ 4 & \text { (b) } \\\hline\end{array}$$

A) (a) = $3.00; (b) = $3.00
B) (a) = $5.00; (b) = $4.00
C) (a) = $2.50; (b) = $2.00
D) (a) = $5.00; (b) = $2.00