Explanation:

- Land: Cultivation of land for agriculture is a fundamental activity in the primary sector.

- Forest: Activities such as forestry and logging are part of the primary sector as they involve the direct extraction of natural resources.

- Mines: Mining is a primary sector activity since it involves the extraction of minerals and raw materials from the earth.

Answer: Option 4 - All of the above.

All these activities involve the extraction and utilization of natural resources, placing them in the primary sector.