Answer:
A. the digestive, muscular, and respiratory
Explanation:
Muscle weakness affects the muscular system (muscles are in the muscular system) , stomach pain affects the digestive system (stomach is a part of the digestive system), and coughing affects the respiratory system (coughing hinders the ability to breathe properly).
When someone is HIV positive it is their immune system is deficient this can lead to AIDS or other serious infections
