Which two statements are true regarding an Ethernet collision domain?（）

• A、If a switch is used, the collision domain includes all devices connected to the switch.
• B、If a hub is used, the collision domain includes all devices connected to the hub.
• C、If a hub is used, the collision domain is limited to each device and the hub.
• D、If a switch is used, the collision domain is limited to each device and the switch.