Statement I is true because the α and β forms of D-(+)-glucose are cyclic hemiacetals that differ only in the configuration of the hydroxyl group at C1, which is the anomeric carbon. Such isomers are called anomers.
Statement II is true because the open chain structures of D-glucose and D-fructose have identical configurations at C3, C4, and C5. D-glucose is an aldohexose with chiral centers at C2, C3, C4, and C5, while D-fructose is a ketohexose with chiral centers at C3, C4, and C5. The stereochemistry at C3 (hydroxyl group on the left), C4 (hydroxyl group on the right), and C5 (hydroxyl group on the right) is exactly the same in both sugars.
Therefore, both Statement I and Statement II are true.
Answer: Both Statement I and Statement II are true