List 3 things you must do before you can use somebody else's work that is protected by copyright.

To copyright something, only three elements are required: (1) fixation, (2) originality, and (3) expression. (1) Fixation: a creative idea must be locked in a permanent state. To protect a song, for example, it must be notated on paper or recorded onto tape or CD.

Explanation:

The sentence whose style is most appropriate with respect to clarity and simplicity of language is the first one - For centuries, art admirers have been digging through records of the painting to figure out its meaning.
The other sentences use language that is quite complicated.