Which of the following is not TRUE about target costing ?
选项：

A: Target costing calculates a selling price by adding a profit margin to the cost ;
B: Target costing involves setting a selling price by reference to the market and then deducting your desired profit margin to leave you with a target cost ;
C:Target costing calculates a target cost by deducting a profit margin from a desired selling price ;
D: Target costing involves setting a selling price by reference to the market and then adding your desired profit margin to leave you with a target cost.