The best answer to the question is:
d. natural artistic pieces formed without human influence
Explanation:
1. Earthworks are artistic pieces created using natural materials found at the site without direct human intervention.
2. These pieces often utilize elements like rocks, soil, plants, and other natural components to create art that blends into the environment without altering it significantly.
3. Earthworks are usually temporary installations that interact with and respond to the natural landscape, highlighting the relationship between art and nature.
Therefore, option d is the most fitting description of Earthworks as they are natural artistic pieces formed without direct human influence.
