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