Final answer:
The revised closing paragraph is polite and encourages a prompt response to ensure the air-conditioning system is ready for the summer.
Step-by-step explanation:
The critique of the closing paragraph provided suggests that it could benefit from being more concise and direct. Each option presented attempts to refine the message and urgency in various ways, but some are more effective than others.
- Option (a) is concise but somewhat lacks warmth or personal touch.
- Option (b) is clear and polite, asking for a quick response directly connected to the appointment.
- Option (c) emphasizes the importance of the timely response for the summer season but might read as overly stern.
- Option (d) presents a courteous and comprehensive finishing touch, requesting early action without sounding too pressing.
Based on these considerations, the rewritten closing paragraph that balances urgency with professionalism could read as: "Please reply promptly to ensure we can order the necessary parts in advance of your service appointment, guaranteeing your air-conditioning system operates efficiently for the summer season."