The correct options are
A Circulatory system
B Excretory system
D Respiratory system
Homeostasis is the ability to maintain a constant internal environment. Various systems in the human body help in homeostasis. Temperature, pH, water balance, electrolyte concentration, etc., are maintained by homeostasis.
∙ Blood flow and sweat from skin helps in maintaining the body temperature.
∙ Excretory system helps in eliminating wastes like urea, ammonia, etc.
∙ Respiratory system eliminates carbon dioxide which is involved in maintaining the pH of blood.
∙ Reproductive system helps in maintaning the continuity of species and is not involved in homeostasis.