Final answer:
Scheduling respiratory therapy before each meal is the most helpful intervention to stimulate appetite in a patient with COPD.
Step-by-step explanation:
The intervention that would be most helpful in stimulating appetite in a patient with COPD who is refusing to eat is c) Scheduling his respiratory therapy before each meal. This intervention can help to reduce shortness of breath and fatigue that may be experienced during meals, making it easier for the patient to eat. By scheduling respiratory therapy before meals, the patient can have improved respiratory function and increased energy to eat.