Which three statements regarding classification and marking in IP packets are true? $($Choose three.$)$

Classification and marking occur in the ToS byte for IPv$4$ packets.

Classification and marking occur in the ToS byte for IPv$6$ packets.

Classification and marking occur in the traffic class byte for IPv$4$ packets.

Classification and marking occur in the traffic class byte for IPv$6$ packets.

The three most significant bits of the ToS or traffic class byte are called IP precedence, and the other bits are unused.

The three most significant bits of the ToS or traffic class byte are called DSCP$,$ and the other bits are unused.