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