A network interface port has collision detection and carrier sensing enabled on a shared twisted pair network. From this statement, what is known about the network interface port?（）
- AThis is a 10 Mb/s switch port.
- BThis is a 100 Mb/s switch port.
- CThis is an Ethernet port operating at half duplex.
- DThis is an Ethernet port operating at full duplex.
- EThis is a port on a network interface card in a PC