The primary difference between a static budget and a flexible budget is that a static budget Oa is concerned only with future acquisitions of fixed assets, whereas a flexible budget is concerned with expenses that vary with sales Ob. is a plan for a single level of activity, whereas a flexible budget adjusts for changes in the activity level Oc. is suitable in a volatile demand situation while a flexible budget is suitable in a stable demand situation Od includes only fixed costs, whereas a flexible budget includes only variable costs