One Reason for Adopting a Plan Whereby the Salespeople Pay

One reason for adopting a plan whereby the salespeople pay their own expenses is that:

A) Often the sales representatives prefer such a plan,because it gives them more freedom of operation.
B) It is considered good management to combine sales force compensation and expenses in one plan.
C) It increases management's control over the sales reps' activities.
D) Many companies use such a plan when their sales forces are paid a straight salary.
E) It eliminates arguments between management and the sales force regarding expenses.