Moderna Pharmaceuticals is trying to estimate the breakeven volume of sales on its

newly developed bivalent COVID$-19$ vaccine. Which of the following would be

expected to reduce the number of vaccine doses that Moderna would need to sell to

breakeven, assuming everything else remains the same?

A decrease in the market price per vaccine dose

An increase in total fixed production costs

An increase in the unit $($per dose$)$ contribution margin

An increase in the variable production cost per dose