How does SDS facilitate the separation of proteins by size during electrophoresis?

• A. SDS increases the protein's charge, enhancing separation by charge.
• B. SDS binds to proteins, increasing their size for easier separation.
• C. SDS masks the protein's charge, making all proteins negatively charged, allowing separation by size.
• D. SDS changes the protein's pH, allowing separation by pH.

Answer: (C)