Which of the following is true of a flexible budget?

a.It enables a firm to compute expected costs for a range of activity levels.

b.It is used to measure whether or not a manager accomplishes his or her goals.

c.It is prepared by large firms only.

d.It is a budget created in advance that is based on a particular level of activity.

e.It is usually not a good choice for benchmarks while preparing a performance report.