The correct answer is: B. Metabolic wastes from a cell.
Excretion is the process by which organisms eliminate waste products from their bodies. These waste products are produced as a result of metabolism, the chemical reactions that take place in cells to produce energy and build new molecules. Some metabolic wastes are toxic, and if they are not removed from the body, they can build up and cause damage to cells and tissues.
The main organs involved in excretion are the kidneys, lungs, skin, and digestive system. The kidneys filter the blood and remove waste products in the form of urine. The lungs remove carbon dioxide from the blood as we breathe out. The skin helps to remove water and salt through sweating. And the digestive system eliminates undigested food waste.
Excretion is essential for maintaining homeostasis, the internal balance of the body. By removing waste products, the body is able to keep its levels of nutrients, hormones, and other substances in check. This helps to ensure that cells and tissues are able to function properly.
Undigested material from the digestive tract is not considered a waste product, as it is not produced by the body. Toxic wastes are not removed by the process of cyclosis, which is a type of cell movement. And water molecules are not considered waste products, as they are essential for life.