1a. "Variable costs are always relevant, and fixed costs are always irrelevant." Do you agree? Why? Ib. "In CVP analysis, gross margin is a less-useful concept than contribution margin." Do you agree? Explain briefly. 1c. "Budgeted performance is a better criterion than past performance for judging managers." Do you agree? Explain 1d. "A component part should be purchased whenever the purchase price is less than its total manufacturing cost per unit." Do you agree? Why? le. How can managers develop a flexible budget? What is variance? Is it useful for managers to preparing flexible budgets and identifying variances