Which of the following statements is/are true? Select one: a. When managers intentionally set budgeted costs too low and budgeted revenues too high, they are creating budgetary slack. b. Production and inventory budgets form the basis for developing the sales budget. c. In a production budget, beginning inventory in units plus budgeted units to be produced equals unit sales plus targeted ending inventory in units. d. All of the given statements are true e. One disadvantage of participative budgeting is employees' tendency to overestimate of revenues.