Choice "C" is correct. An increase in anticipated sales of petrol relative to sales of septine and tridol will decrease the breakeven point. This is because the product mix has changed in favor of the more profitable (higher contribution margin) products. The composite contribution margin is higher, and the breakeven point is lower.Choice "d" is incorrect. The effect on breakeven cannot be determined.Choice "a" is incorrect. An increase in market will not affect breakeven unless the price of the product changes.Choice "b" is incorrect. An increase in material cost will decrease contribution margin and increase breakeven.