Final answer:
The Database Management System (DBMS) oversees logging every data transaction in an information system, ensuring data integrity and security.
Step-by-step explanation:
The function of the component you are asking about, which oversees if every data transaction made by an employee is logged in the information system, is typically handled by the Database Management System (DBMS). A DBMS is designed to manage and maintain the integrity of databases and ensure that all data transactions are performed correctly and securely. It records transactions, which can be used for auditing, tracking changes, and ensuring that all access and modifications to the database are properly logged for security and compliance purposes. The Central Processing Unit (CPU) does not perform this function; it processes instructions. The Chief Information Officer (CIO) is a job role focused on the overall technology strategy and not routine data transaction logging. Lastly, the Network Interface Card (NIC) is hardware that connects a computer to a network, and it’s not involved in transaction logging within a database.