Silvio enterprises produced three products, with cost and selling price as follows:
model b3 model d7 model 5
selling price per unit $42 100% $34 100% $50 100%
variable cosr per unit $18 45% $12 40% $36 72%
contribution margin $24 55% $22 60% $14 28%

each product requires a certain number of minutes on the drill press. there is only one drill press available so it is the constraint for this product. model d7 requires 2 minutes of drill press time, model b3 requires 1 minute of drill press time, and model f5 requires 7 minutes of drill press time. in what order should silvio enterprises emphasize its products to maximize its contribution margin? (rank the products in order from most profitable to least profitable.)

(a) model b3, d7, f5
(b) model d7, b3, f5
(c) model b3, f5, d7
(d) model f5, d7, b3