Propose a scenario where proline's cyclic structure could affect protein function, and explain the potential outcome.

• A. Proline's cyclic structure could allow for more hydrogen bonding, stabilizing the protein.
• B. Proline's cyclic structure could lead to increased hydrophilicity, improving protein solubility.
• C. Proline's cyclic structure could lead to increased flexibility in a protein, enhancing its function.
• D. Proline's cyclic structure could cause a kink in the protein chain, potentially disrupting its function.

Answer: (D)