I would like to know the difference between unit-level, batch-level, product-level, or organization-sustaining activity? to be able to determine below which they belong to.

• Is this unit-level, batch-level, product level or organization sustaining activity? Receive raw materials from suppliers.
• Is this unit-level, batch-level, product level or organization sustaining activity? Manage parts inventories
• Is this unit-level, batch-level, product level or organization sustaining activity? Do rough milling work on products.
• Is this unit-level, batch-level, product level or organization sustaining activity? Interview and process new employees in the personnel department.
• Is this unit-level, batch-level, product level or organization sustaining activity? Design new products.
• Is this unit-level, batch-level, product level or organization sustaining activity? Perform periodic preventive maintenance on general-use equipment.
• Is this unit-level, batch-level, product level or organization sustaining activity? Use the general factory building.
• Is this unit-level, batch-level, product level or organization sustaining activity? Issue purchase orders for a job.