Which of the following correctly describes the purpose of layer $1$ or the physical layer in networking?

Layer $1$ or the physical layer is responsible for carrying structured information over the network and defines how to transmit and receive raw bit streams.

Layer $1$ or the physical layer is responsible for carrying unstructured information over the network and defines how to transmit and receive raw bit streams.

Layer $1$ or the physical layer is responsible for carrying unstructured information over the network and defines how to encode and decode structured data.

Layer $1$ or the physical layer is responsible for carrying structured information over the network and defines how to encode and decode unstructured data.