What is the role of van der Waals interactions in biological molecules?

• A. Van der Waals interactions are too weak to be significant.
• B. Van der Waals interactions are strong bonds that play a major structural role in holding proteins together.
• C. Van der Waals interactions are important only in water.
• D. Although they are weak bonds, van der Waals interactions help to reinforce the three-dimensional shapes of large molecules.