Answer:
be durable
Step-by-step explanation:
From the scenario described the Engineers have met one of the main criteria which is for it to be durable. A design needs to be made with a material that is available, durable, and cheap in order for it to be as efficient as possible while also selling and being profitable. By finding the material polycarbonate they have made sure that the design will be durable as well as cost-efficient since the material is "not too costly". Now if they are able to acquire the material in large quantities then they would have met the availability criteria as well.