Propose a mechanism by which cooperative stepwise interactions could be experimentally demonstrated in a laboratory setting.

• A. Use site-directed mutagenesis to alter specific amino acids and observe changes in folding kinetics.
• B. Determine the protein's molecular weight using gel electrophoresis.
• C. Analyze the protein's secondary structure using circular dichroism.
• D. Measure the melting temperature of a protein in different solvents.

Answer: (A)