The "Purchase_list" table in a relational database manages the purchases of products. This table should be normalized and divided into a "Purchase" table and a "Product" table. Which of the following is the most appropriate field that should be contained in common in the two divided tables? [Purchase_list table] Purchase_number | Product_number | Product_name | Count | Unit_price | Payment_method | Delivery_date Note: Each purchase includes only one product, identified by Purchase_number. Each product is uniquely identified by Product_number.