Answer:
Options B and C are the two criteria that are most essential
Step-by-step explanation:
When trying to develop a novel process, it is important that the new process involves the use of equipment that can be operated safely by workers so as to prevent death or injury in the cause of handling this equipment. If this equipment is seen not to be safe or cannot be handled safely by workers, it can/will force workers to previous or alternative methods that require more safe equipment.
Also, the process must be able to maximize the most of the reactants, i.e the process must be able to convert a good percentage of the reactants into the desired product (phosphorus pentachloride) since that is the focus. This will also lead to reduction of byproducts produced which could be useful or otherwise (a loss).