A. This is correct. By allowing managers to participate in the budgeting process with the objectives of senior management in mind, the managers can evaluate the department and find the most optimal, and realistic, means to achieve the targets.
B. Budget discussions on a daily basis are a bit excessive and not an efficient way to conduct business. Generally there is a budget "season" where the development of the budget is the primary focus, and daily discussions are not unusual. After budget season; however, the communication between managers and their superiors would likely not focus solely on budget matters, although it would cover variances from the budget.
C. Enacting policies that "control" the budget process can result in resentment and ineffective efforts from departmental management. This is not the best way to generate a realistically challenging budget.
D. Building slack into a budget is not going to be in the organization’s best interest in the long run.