Which of the following applications can be developed using Visual Basic tool?

Visual Basic is a versatile programming tool that can be used to develop various types of applications, including:

Graphical User Interface (GUI) Applications: Visual Basic is particularly well-suited for creating applications with graphical user interfaces. It provides a drag-and-drop interface for designing windows, buttons, menus, and other visual elements that users interact with.
Real-time Applications: Visual Basic can also be used to develop real-time applications, where timely processing and responses are critical. While it might not be the primary choice for extremely high-performance real-time applications, it can certainly handle a wide range of real-time tasks.
Character User Interface (CUI) Applications: While Visual Basic's strengths lie in creating GUI applications, it's not limited to that. It can also be used to develop character-based or console applications, although its design principles are more aligned with GUI development.

Therefore, the correct option is Option D: All of the mentioned, as Visual Basic is capable of developing applications with graphical user interfaces, real-time capabilities, and even character user interfaces to some extent.