Work centers W, X, Y, and Z are available for 40 hours per week and have no setup time when switching between products. Market demand for each product is 80 units per week. In the questions that follow, the traditional method refers to maximizing the contribution margin per unit for each product, and the bottleneck method refers to maximizing the contribution margin per minute at the bottleneck for each product. Using the bottleneck method, what is the optimal product mix (consider variable costs only-overhead is not included in this profit calculation)