Final answer:
The most important reason for the client to exercise after a mastectomy is to enhance lymphatic drainage and reduce swelling in the affected arm, which is crucial for the client's recovery and quality of life.The correct option is c).
Step-by-step explanation:
The most important reason for a client who recently had a modified radical mastectomy to exercise the affected arm is c) It enhances lymphatic drainage and reduces swelling. After a mastectomy, there is often a disruption in the normal flow of lymph, which can lead to lymphedema, characterized by swelling in the arm. Properly prescribed exercises can help to improve lymph flow, preventing or managing swelling and thereby improving the client's quality of life. Exercise also plays a role in muscle atrophy prevention, ensuring that the muscles do not lose strength due to disuse. While exercise contributes to cardiovascular health and may indeed promote better scar healing, the specific concern post-mastectomy is the reduction of lymphatic congestion to minimize complications.