Which of the following ensures the security of unauthorized access to data?

Enforcement of integrity constraints is crucial for ensuring the security of unauthorized access to data because it establishes rules that data must adhere to within a database. These constraints help to preserve the accuracy and reliability of the data, ensuring that any information stored is valid and consistent. By defining guidelines for permissible data inputs and relationships, integrity constraints effectively prevent unauthorized alterations or entries that could compromise the security of the information.

This approach assists in maintaining the confidentiality, integrity, and availability of the data by allowing only approved changes and interactions based on established criteria. For example, constraints can restrict the types of data entered into certain fields or ensure that relationships between data entities are valid. By enforcing these rules, organizations can significantly mitigate the risk of unauthorized access and manipulation of sensitive data, thereby enhancing overall data security.

In contrast, other options do not focus primarily on preventing unauthorized access. Transaction processing refers more to the handling of collections of operations that must be completed successfully, while backup and recovery strategies concern data preservation and restoration rather than access control. Data sharing primarily involves allowing users to access and use the data, which can be contrary to the goal of preventing unauthorized access. Therefore, the enforcement of integrity constraints is the strongest option for protecting against unauthorized data access.