In the context of budgetary control, certain costs are not amenable to the use of flexible budgets. These include some costs which are often called 'discretionary' (or 'programmed').

You are required to explain:

(a) the nature of discretionary (or programmed) costs and give two examples;

(b) how the treatment of these costs differs from that of other types of cost in the process of preparing and using budgets for control purposes