Which of the following formats is supported for an extraction file?

The .txt format is supported for extraction files in Adobe Campaign Classic. This format is a plain text type, which allows for simple and straightforward storage of data without the overhead of complex structure. When data is extracted into a .txt file, it can be easily manipulated and read by various applications, making it user-friendly for many purposes, such as reporting or further data processing.

The other formats, while they may be widely used and recognized in the data handling ecosystem, are not universally applicable for extraction purposes within Adobe Campaign Classic. For example, while .csv files are prevalent for tabular data, .xml is structured and suited for complex data representation, and .json is largely used for data interchange in web applications. However, the specific context of supported extraction formats primarily highlights .txt as a straightforward and practical choice for Adobe Campaign Classic's functionality.