Springer Products Manufactures Three Different Product Lines, Model X, Model

Springer Products manufactures three different product lines, Model X, Model Y, and Model Z. Considerable market demand exists for all models. The following per unit data apply:

Which model has the greatest contribution margin per machine-hour?

A) Model X
B) Model Y
C) Model Z
D) Both Model X and Model Y have the highest and same contribution margin per machine-hour