Which of the following statements correctly describes a disadvantage of using a flexible budgeting system? A flexible budgeting system is quite expensive to design, implement, and maintain. If a project uses resources that are used in other areas of the organization, a B. flexible budgeting system may not give an accurate estimate of its costs. A flexible budgeting system is based on a set of assumptions that may not come true. D. A flexible budgeting system is only useful for control purposes, not planning purposes