The thickness of each sheet in montmorillonite is______________

• A. 5 ‚Äö√†√∂‚àö√±
• B. 7 ‚Äö√†√∂‚àö√±
• C. 10 ‚Äö√†√∂‚àö√±
• D. 15 ‚Äö√†√∂‚àö√±