Which of the following is not a feature of DBMS?

CONCEPT: A Database Management System (DBMS) is software built to let many users store, retrieve, and modify shared data at the same time while the system enforces integrity, security, and controlled concurrent access on their behalf. Reducing redundant storage of the same data and protecting data through authentication and access control are exactly the kinds of guarantees a DBMS is designed to provide. APPLICATION: Checking each listed capability against that idea: keeping duplication and redundancy to a minimum is a genuine DBMS capability, achieved through normalization and centralized storage. Providing a high level of security is also genuine, delivered through user authentication, authorization, and access-control mechanisms. Restricting the system to a single user at a time, however, is the opposite of what a DBMS provides — a DBMS is specifically engineered for concurrent multi-user access, using locking and concurrency-control protocols so many users can work with the same data simultaneously without corrupting it. So exactly one of the listed items fails to describe something a DBMS actually offers. CROSS-CHECK: Since only one listed item fails to describe a genuine DBMS capability, an option claiming that more than one of them is not a feature over-counts the exceptions, and an option claiming that none of them is an exception under-counts them — both are ruled out by the same check. The item describing single-user-only access remains the sole exception, since a DBMS is built around shared, simultaneous, multi-user access rather than restricting access to one user.