Which of the following is an example of a semi-fixed (semi-variable) cost? O A. Cost of telephone calls. OB. Total telephone account, both calls and rental. O C. Cost of telephone rental OD. None of the above If historical costs are irrelevant for decision-making, why do we spend so much time analysing them? O A. Historical costs can be used as a direct substitute for future costs as prices rarely fluctuate. OB. The change in future costs is often the same as the change in historical costs O C. Historical cost behaviour is often the starting point by which the relevant future cost may be estimated. OD. The trends of historical costs can be used to make predictions in the trends of future costs. Which of these would be considered a fixed cost? O A. Materials used in production OB. Insurance premium O c. Laundry costs to wash towels used by a hairdresser OD. Cost of fuel for a transport company