A Company Produces Three Product Lines and a Different Marketing

A company produces three product lines and a different marketing manager is responsible for each line. Most marketing expenses are specific to each line, but a common sales force sells all three lines. Sales reps are paid by commission, with a different commission for each product line. In this case, in a marketing cost analysis,

A) the contribution-margin approach would probably divide personal selling expense based on commission expense for each product line.
B) a full-cost approach would ignore commission expense since it is not a fixed cost.
C) sales commissions are a variable expense and would not be considered in the contribution-margin approach.
D) the full-cost approach would be easier to do if all sales reps were paid a straight salary.
E) None of the above is true.