Information from the Records of the Conundrum Company for September

Information from the records of the Conundrum Company for September 2018 was as follows: $\begin{array} { l r } \text { Sales } & \$ 307,500 \\ \text { Selling and administrative expenses } & 52,500 \\ \text { Direct materials used } & 66,000 \\ \text { Direct labor } & 75,000 \\ \text { Variable factory overhead } & 50,000 \\ \text { Factory overhead } & 51,250 \end{array}$

Inventories
$\begin{array}{lcc}&\text { Sept. 1,2018}&\text { Sept 30,2018 }\\\hline\text { Direct materials } & \$ 8,000 & \$ 10,500 \\\text { Work in process } & 18,750 & 21,000 \\\text { Finished goods } & 17,250 & 14,250\end{array}$ Conundrum Corporation produced 20,000 units.
If production increased to 32,000 units next year, what is the effect on variable product costs per unit and total product costs per unit respectively?

A) remain the same; remain the same
B) remain the same; decrease
C) increase; remain the same
D) decrease; increase