All the glucose units in dextran have six-membered rings. When a sample of dextran is treated with methyl iodide and silver oxide and the product is hydrolyzed under acidic conditions, the products obtained are 2,3,4,6-tetra-O-methyl-D-glucose, 2,4,6-tri- O-methyl D-glucose, 2,3,4-tri-O-methyl-D-glucose, and 2,4-di-O-methyl-D-glucose. Draw a short segment of dextran.