Which of the following statements regarding proteoglycans is true?

Ans-D. All of these* Proteoglycans contain many long unbranched polysaccharide chains attached to a core protein.* The polysaccharide chains, called glycosaminoglycans, are composed of repeating disaccharide units containing oxidized acid sugars (such as glucuronic acid), sulfated sugars, and N-acetylated amino sugars.* The large number of negative charges causes the glycosaminoglycan chains to radiate out from the protein so that the overall structure resembles a bottlebrush.The proteoglycans are essential pas of the extracellular matrix, the aqueous humor of the eye, secretions of mucus-producing cells, and cailage.