In which database model does each record have a unique identifier and can have…

The correct answer is the Network model. In this database structure, each record possesses a unique identifier known as an owner or key, allowing it to be distinctly identified within the system. Unlike the Hierarchical model, where a child record can have only one parent (forming a strict tree structure), the Network model permits a record to maintain multiple relationships with different parents. This many-to-many relationship capability is the defining characteristic that distinguishes it from simpler models.\nWhile the Relational model uses tables and keys, it does not inherently define parent-child relationships in this specific structural manner. Similarly, the Object-oriented model focuses on objects and classes rather than these specific record linkage rules. Therefore, because the Network model explicitly supports multiple parents for a single child while ensuring unique identifiers, it is the only option that fits the description provided in the question.