Hint Earthworm is an invertebrate that is terrestrial and belongs to Opisthopora and has a tube within a tube body plan with segmented internal segmentation and setae on all the segments. They are commonly found in the soil and eat a variety of organic matter which includes plant matter, protozoa nematodes, bacteria, fungi, rotifers, and other microorganisms.
Urea is the major nitrogenous excretory material of earthworm. Earthworm excretes carbon dioxide and nitrogen is waste as their main waste materials and the carbon dioxide is excreted from the body through its moist skin which is known as diffusion. The nitrogenous waste is excreted from the body by special excretory organs which are known as nephridia. It is a tubular coiled structure which is a rounded funnel-shaped nephrostome. Nephrostome is opened in a coiled tube known as nephridial tubule which is lined with cilia. It opens outside the body through a small opening known as nephridiopore. Earthworm consists of a body fluid that is rich in nitrogenous waste and passes through a nephridial tubule where it gets absorbed. The highest percentage of nitrogenous waste is excreted out from the body and the remaining fluid through nephridiopore with movements of cilia.
Uric acid: Uric acid is different in different organs and consists of a correlation between uric acid in the organs and the gene expression. It is formed from ions in Salt of ammonium acid urate. Uric acid is the product of the metabolic breakdown of purine nucleotides which is a normal component of urine. It can lead to gout if the high blood concentrations of uric acid take place and it is associated with other medical conditions which include diabetes and the formation of ammonium acid urate kidney stones.
Amino acids: They are organic compounds that consist of amino and carboxyl functional groups and are classified in many ways. It is the second-largest component of human muscles and tissues and participates in several processes such as neurotransmitter transport and biosynthesis. They make proteins and join together to form short polymer chains which are known as peptides and these polymers are linear and unbranched with each amino acid attached to two neighboring amino acids.
So, the correct answer is 'urea'.
Note: There are over 6,000 species of earthworm worldwide and more than 180 species of an earthworm are found in the US and Canada in which 60 are invasive species. they do not consist of lungs or other specialized respiratory organs and breathe through their skins which exudes a lubricating fluid which helps in movement under burrows.