please answer all the questions and give explanations. Will get a thumbs up if correct.

QUESTION 16 Flexible budgets typically change which costs O All costs O Fixed Costs O Variable Costs QUESTION 17 Differences between budgeted and actual amounts are called: O Deviations O Variances O Differential Amounts O Discrepancies QUESTION 18 Budget difference must always be investigated by management to achieve effective control. True O False QUESTION 19 A benefit of budgeting is that it provides definite objectives for evaluating performance O True O False QUESTION 20 Companies generally obtain sales forecasts from many different sources True False