What is the primary difference between pyranose conformations and configurations?

• A. Conformations are permanent and fixed, while configurations are flexible and can change without breaking bonds.
• B. Conformations are related to the chemical composition, while configurations are related to the physical structure.
• C. Conformations involve breaking and reforming bonds, while configurations do not.
• D. Conformations are flexible and can change without breaking bonds, while configurations require breaking and reforming bonds.

Answer: (D)