The correct answer is: B. multiple.
MDI stands for Multiple Document Interface. It is a user interface model that allows multiple documents to be opened and displayed within a single parent window. The parent window is called the MDI parent window, and the child windows are called MDI child windows.
The main property of MDI is that it allows multiple documents to be opened and displayed within a single parent window. This is in contrast to the single document interface (SDI), which only allows one document to be opened and displayed at a time.
MDI is often used in applications that need to display multiple documents, such as word processors, spreadsheets, and image editors. It can also be used in applications that need to display multiple views of the same document, such as database applications and project management applications.
The following are the four options for the question:
- A. mdi child: This is not a valid option.
- B. multiple: This is the correct option. MDI allows multiple documents to be opened and displayed within a single parent window.
- C. list: This is not a valid option.
- D. background: This is not a valid option.
I hope this helps! Let me know if you have any other questions.