Which of the following statements is true? Multiple Choice O A flexible budget is a comparison of actual revenues and costs at the actual level of activity to the actual revenues and costs incurred at the planned level of activity. O A flexible budget is a comparison of actual revenues and costs to what they should have been given the planned level of activity. O A flexible budget is an estimate of what revenues and costs should have been given the planned level of activity for the period. O A flexible budget is an estimate of what revenues and costs should have been given the actual level of activity for the period