A Typical 3D Game Engine Can Usually Use Artificial Intelligence

A typical 3D game engine can usually use artificial intelligence (AI) . What does this entail?

A) Refers to the way in which objects "think" and react to stimuli provided by the player
B) The concept of physics
C) This is akin to the glue that holds everything together in a game
D) Keeping track of all the items in a game, whether they are textures, 3D models, sounds, surfaces, etc.