Which component of an Ethernet frame is used to notify a host that (CCNA 200-301)

Correct answer: C) preamble.
The preamble is used in an Ethernet frame to notify a host that traffic is coming. The preamble is a sequence of bits that signals the beginning of a frame. It is designed to ensure that the receiving device is ready to receive data. When the receiving device detects the preamble, it knows that a frame is about to be transmitted, allowing it to prepare for the incoming data. This mechanism helps in synchronizing the sender and receiver, ensuring that the data is correctly interpreted and processed.