Which of the following is a WYSIWYG editor used in Mendix?

The WYSIWYG (What You See Is What You Get) editor used in Mendix is known as the Studio. This tool allows users to create applications visually, providing a real-time representation of the application as it is being built. Users can drag and drop components onto a canvas, making it easy to see how changes will appear in the final product without needing to write extensive code. This intuitive interface streamlines the development process, particularly for those who may not have a strong programming background.

In contrast, Modeler refers to Mendix Modeler, which is typically more focused on logical design and backend configurations rather than a visual editing experience. Workbench is a term often associated with tools or platforms that assist in various aspects of development, but it is not specifically a WYSIWYG editor. Lastly, Designer may imply some form of editing tool, but it does not encompass the full range of WYSIWYG features that Studio offers. Therefore, Studio is the correct choice for a WYSIWYG editor within the Mendix ecosystem.