Why do silanol groups on silica columns cause tailing for basic compounds, and how can this be mitigated?

Why do silanol groups on silica columns cause tailing for basic compounds, and how can this be mitigated?

• A. Silanol groups act as acidic sites that interact with basic analytes causing tailing; mitigation includes end-capped columns, using mobile-phase buffers, adding basic modifiers (e.g., triethylamine) or adjusting pH to reduce ionization of analyte.
• B. Silanol groups are basic sites that interact with acids causing tailing; mitigation includes lowering temperature.
• C. Silanol groups cause broad peaks; mitigation is increasing flow rate.
• D. Silanol groups have no effect on peak shape; mitigation is using higher detector sensitivity.

Answer: (A)