Which of the following output formats is supported by the SET SQLFORMAT command?

The SET SQLFORMAT command is used in SQL environments to specify the output format of query results. Among the choices provided, JSON is an increasingly popular data interchange format that is supported by various database management systems, allowing for structured data to be easily shared and utilized. This capability is particularly beneficial for modern web applications and data services that require a lightweight format for data transfer.

In contrast, while PDF, XML, and HTML might be used for different purposes in data representation or documentation, they do not align with the typical output formats that the SET SQLFORMAT command would directly support for raw SQL query results. PDF is mostly used for document presentation, XML serves as a markup language that can be used for data storage or transmission but is not necessarily handled directly by the SET SQLFORMAT command in the context of SQL outputs. HTML is primarily used for web page content and formatting, rather than for structured SQL output.

Therefore, JSON stands out as the correct answer, as it specifically relates to the output of structured query results in a way that aligns with modern programming needs and practices.