Which two statements are true regarding GRE tunnel overhead? (Choose two.)
A . If the host sends a packet larger than the MTU, that packet must be dropped.
B . Packets are not dropped because the router clears the DF bit for GRE traffic by default.
C . Packets larger than the MTU are fragmented or dropped depending on the DF bit setting.
D . You can change the tunnel MTU to avoid packet fragmentation or drops.