Which of the following languages is used as a scripting language in the Unity 3D game engine?

The answer is C# (C Sharp) because it has been the primary scripting language used in the Unity 3D game engine since its early versions. C# is a versatile and powerful programming language that provides a wide range of features and functionalities required for game development, including object-oriented programming, easy integration with Unity's API, and strong support for building complex game mechanics and systems. Moreover, C# offers a smooth workflow and a robust development environment within the Unity editor, making it the preferred choice for scripting in Unity 3D.