Amie has a sales team of 3 people. She compensates them according to each of their productivities and performance. This is called Straight-Commission Plan. What is Amie's incentive plan's weakness? Select one: a. Clerical costs are higher than for either a salary or a commission system. b. Salespeople only do an average rather than an outstanding job. c. It provides little financial control over sales people's activities, a weakness further compounded when they pay their own expenses. d. All sales personnel need rating not only on their achievement of sales and cost goals but on their performance of each assigned duty