What does qos pre-classify provides in regard to implementing QoS over GRE/IPSec VPN tunnels?

A.
enables IOS to make a copy of the inner (original) IP header and to run a QoS classification before encryption, based on fields in the inner IP header.

B.
enables IOS to classify packets based on the ToS field in the inner (original) IP header.

C.
enables IOS to classify packets based on the ToS field in the outer tunnel IP header.

D.
enables IOS to copy the ToS field from the inner (original) IP header to the outer tunel IP header.

E.
enables the IOS classification engine to only see a single encrypted and tunneled flow to reduce classification complexity.