Whales, Inc. produces Item D, Item E, and Item F. Considerable market demand exists for all products. The following per unit data apply:

Item D Item E Item F

Selling price $72 $58 $74

Direct materials 8 8 8

Direct labor ($16 per hour) 32 16 32

Variable support costs ($4 per machine-hour) 12 16 12

Fixed support costs 12 12 12

If there is excess capacity, which model is the most profitable to produce and why? If there is a machine breakdown, which model is the most profitable to produce and why? If there is a labor shortage, which model is the most profitable to produce and why?