The main excretory organ of the body is _____?

1. Liver
2. Skin
3. Kidney
4. Lungs

The kidneys are the primary excretory organs in the human body. They filter blood to remove waste products and excess substances, forming urine. While the liver processes toxins, the skin excretes sweat, and the lungs exhale CO2, the kidneys are responsible for the main and most critical filtration and excretion process.