Which of the Following Statements Is Not True

Which of the following statements is not true.

A) In a static budget system, a budget is not modified once the actual volume of sales is known.
B) A flexible budget is a control technique that can be used because it can be hard for an organisation to accurately predict its sales volume in a future period.
C) Fixed costs are reported as the same amount in a static and a flexible budget.
D) A labour rate variance arises if the actual wage rate differs to the budgeted wage rate.
E) If the flexible budget figure for material costs is more than the actual figure for material costs, there must be a favourable material price variance.