Which document would you write to ask about the procedures for obtaining a service?

The best choice is to write an inquiry letter when seeking information about procedures for obtaining a service. An inquiry letter is specifically designed to request information or clarification regarding a particular issue, process, or service. It is structured to formally address the recipient and pose questions, making it clear that you are looking for specific guidance or details.

In this context, an inquiry letter allows you to articulate your needs effectively and provides an opportunity for the recipient to respond with relevant information. The tone is typically polite and professional, which is appropriate for communication about services.

Other options, such as a claim letter, progress report, and laboratory report, serve different purposes. A claim letter is used to assert a right to something, typically in response to dissatisfaction or a complaint. A progress report updates stakeholders on the status of a project or process, while a laboratory report documents scientific findings and results. None of these options focuses specifically on inquiring about procedures, making the inquiry letter the most suitable choice for the situation described.