VARIABLE COSTS--RELEVANTE RANGE--CONTRIBUTION MARGIN--BREAK EVEN POINT--FIXED COSTS--SEMIVARIABLE COSTS--ECONOMIES OF SCALE--SALES MIX--UNIT CONTRIBUTION MARGIN Each of the following statement may or may not describe one of the above technical terms. For each statement indicate the accounting term described or answer "NONE" if the statement does not correctly describe any of the terms. A. The level of sales at which revenue exactly equals costs and expenses. B. Costs that remain unchanged despite changes in sales volume. C. The span over which output is likely to vary and assumptions about cost behavior generally remain valid. D. Sales revenue less variable cost per unit. E. Unit sales price minus variable cost per unit. G. Costs that respond to changes in sales volume by less than a proportionate amount. H. Operating income less variable costs