; Audi A6 2nd Gen (C5/4B) Original radio options - InCarTec

There are multiple original radio options in the Audi A6 2nd Gen (C5/4B), which option is the original fitted system?

Audi A6 Navi Plus RNS-D Audi A6 Navi Plus RNS-D
Audi A6 Navi Plus RNS-E Audi A6 Navi Plus RNS-E
Audi A6 Symphony II Audi A6 Symphony II
Audi Concert Audi Concert
Audi Concert II CD Audi Concert II CD