Only sure way is to get the option codes and look them up at:
http://www.renntech.org/forums/index.php?autocom=options&code=carrera
option M339 is the 4 wheel drive; M338 2 wheel drive; M620 e-accelerator (required for M339)
What year is it?
If there is a picture of the dash, you should see to the left of the radio/a-c a "psm off button" thats a good sign a early C4's all have PSM and C2's have Traction control