The complete statement is "Art is a creative expression of an idea in some form."
Let's complete this statement
Art can be viewed as a form of personal expression, where artists communicate their ideas, emotions, and experiences through their chosen medium. This expression can be conscious and deliberate, or it can be more intuitive and unconscious. It can also be seen as a way of communicating with others.
Artists can use their work to share their perspectives on the world (think of concept artist or punk musicians), to evoke emotions, or to challenge existing social norms and values.
So the correct option is C.