Final answer:
The nurse is implementing tertiary prevention strategies in the community by providing case management services for clients with chronic illness.
Step-by-step explanation:
The nurse is implementing tertiary prevention strategies in the community by providing case management services for clients with chronic illness. Tertiary prevention focuses on managing and minimizing the impacts of chronic conditions to prevent further complications and improve quality of life. By providing case management services, the nurse helps clients effectively manage their chronic illnesses and access the necessary resources and support.