Which of the following structures has a better leaving group? Justify your answer.

• A. Structure (b) has a better leaving group because the loss of the leaving group forms a weaker (more stable) base that is neutral.
• B. Structure (b) has a better leaving group because the loss of the leaving group forms a stronger (more stable) base that is charged.
• C. The leaving groups of both structures have the same leaving group ability because of the presence of the oxygen atom.
• D. None of these.