Question：Abbey Enterprises uses a fixed budget within its overall budgetary control process.
　　This budget is usually prepared prior to the start of the budget period.
　　Which of the following statements is not true?
　　A. A fixed budget may be changed if required by the prevailing environment.
　　B. A fixed budget is the same as the master budget.
　　C. A fixed budget is not adjusted for periodic changes in sales and production volumes.
　　D. A fixed budget is based upon the estimated fixed costs of production.
　　The correct answer is:A fixed budget is based upon the estimated fixed costs of production.
　　The fixed budget (master budget) for an organisation is based upon a particular level of activity in a period and the associated costs and revenues for that level of activity.