It is a perfect example of a natural selection.
(I'm not sure if this is the exact answer that you are looking for.)
The answer is c
Because homeostasis is the state of steady internal, physical, and chemical conditions
Chemical composition is always a property of an ore.
Leeches are parasitic because they suck blood not giving any benifit but harm.
Birds, insects, and many reptiles excrete nitrogenous waste in the form of uric acid, which saves water.
Nitrogenous waste in the body tend to form toxic ammonia, which must be excreted. Mammals such as human excrete urea, while birds, reptiles, and some terrestrial invertebrates produce uric acid as waste in the form of a white paste or power. The production of uric acid involves a complex metabolic pathway that is energetically costly in comparison to processing of other nitrogenous wastes such as urea or ammonia, it has the advantages of reducing water loss and, hence, reducing the need for water.
