How does BF3 function as a Lewis acid in thioacetal formation?

• A. BF3 donates protons to the thiols, initiating thioacetal formation.
• B. BF3 accepts electron pairs from oxygen, facilitating the formation of thioacetals.
• C. BF3 forms a complex with carbonyls to initiate the reaction.
• D. BF3 acts as a solvent in the reaction.

Answer: (B)