Which statement describes contention-based access in networking?

Contention-based access in networking refers to a method where multiple devices are allowed to share the same transmission medium. This sharing happens based on a competitive approach, where devices can listen for a clear medium and transmit data when the medium is free. This method is commonly found in networking technologies such as Ethernet, where devices on the same network segment can transmit data. If two devices attempt to send data simultaneously, a collision occurs, and both devices must wait before trying to resend their data.

By allowing multiple devices to share the same transmission media, contention-based access effectively maximizes the usability of the network resources, although it does introduce the possibility of collisions that must be managed through protocols like Carrier Sense Multiple Access with Collision Detection (CSMA/CD). Other access methods, such as time-division multiplexing or fixed channel assignments, do not operate on this contention basis and instead provide deterministic access with less chance for media contention.