Which of the following refers to the management of simultaneous transactions to prevent conflicts?

Concurrency control is the correct choice because it specifically refers to techniques and methods used to manage and coordinate multiple transactions occurring at the same time in a database system. The primary goal of concurrency control is to ensure that these simultaneous transactions do not interfere with each other, which could lead to inconsistent data or conflicts.

In database systems, when multiple transactions are processed concurrently, they might attempt to read or write the same data elements at the same time. Concurrency control mechanisms ensure that transactions are executed in such a way that they reflect a consistent state, protecting the integrity and validity of the database. This is crucial for maintaining data accuracy and reliability, especially in situations where transactions are being processed in real-time.

The other concepts mentioned, while related to transaction management, do not specifically address the simultaneous nature of transactions. Transaction isolation deals with ensuring that transactions do not affect each other's execution, but it’s more about the visibility of data than managing concurrent access directly. Deadlock management refers to techniques for dealing with situations where two or more transactions are waiting indefinitely for each other to release resources. Access control pertains to the permissions and roles assigned to users regarding their ability to retrieve or modify data, rather than managing the interactions of transactions themselves.

Hence, concurrency control is the fundamental