How does router sub$-$interface know about VLAN information that the frame brings from the switchport, it is connected to$?$

Host adds VLAN information at layer $4$ in the TCP protocol suite

VLAN ID information is assigned to all frames reaching a switch core

VLAN ID is removed from each frame that leaves the switch

VLAN ID tag is added by the switchport to the frame entering switchport $($switchport in trunk mode$)$ which forwards frame to router interface

VLAN information is arbitrarily assigned to the frame entering switchport