Concept:Excretion is the process of removing metabolic waste products from the body.
Explanation:Metabolic activities produce waste substances like urea, carbon dioxide, and excess water.
These wastes must be removed to keep the body healthy.
The organs involved include the lungs, skin, and kidneys.
The kidneys form urine and help remove nitrogenous wastes.
This biological process is called excretion.
Respiration is gas exchange, ingestion is taking in food, and egestion is removing undigested food.
Answer:B. excretion