A. The selling price minus all variable costs is the contribution margin, not the throughput contribution margin.
B. This is not the way to calculate the throughput contribution margin.
C. The selling price minus the totally variable cost per unit is the throughput contribution margin per unit. Generally, the only totally variable cost will be the direct materials cost.
The throughput contribution margin per day is the throughput contribution margin per unit multiplied by the number of units that can be produced in a day.
D. This is not the way to calculate the throughput contribution margin.