Sheridan Company sells two types of computer hard drives. The sales mix is 30% (Q-Drive) and 70% (Q-Drive Plus). Q-Drive has variable costs per unit of $135 and a selling price of $180. Q-Drive Plus has variable costs per unit of $150 and a selling price of $225. The weighted-average unit contribution margin for Sheridan is

$54.0.

$66.

$90.0.

$180.