What mode should a network administrator enable to improve data transfer rates to the expected 100 Mbps in a 100BASE-TX network?

Enabling full-duplex mode is essential for achieving the expected data transfer rates of 100 Mbps in a 100BASE-TX network. In full-duplex mode, both the sender and receiver can transmit and receive data simultaneously, effectively doubling the available bandwidth for communication. This capability allows for more efficient data transfer, minimizing collisions and maximizing throughput.

In contrast, half-duplex mode only allows for one device to either send or receive data at any given time, which can lead to congestion and reduced overall performance. While simplex and multicast modes pertain to different types of data transmission, they do not directly influence the overall bandwidth or the ability to maintain higher data transfer rates in a 100BASE-TX setup. Hence, full-duplex operation is the optimal choice to ensure the network achieves and maintains the desired speed.