The correct answer is: D. object browser
The object browser is a tool in Visual Studio that allows you to browse through the various properties, events, and methods that are made available to you. It can be used to view information about objects in your project, as well as objects in other projects that you have referenced.
The properties window is a tool in Visual Studio that allows you to view and modify the properties of an object. The project explorer is a tool in Visual Studio that allows you to view the files and folders in your project.
The object browser is a more powerful tool than the properties window or the project explorer, as it allows you to view information about objects that are not in your current project.