Of the four mentioned as candidates, I'll go for this logic:
If Juve go to B:
1. Roberto Donadoni
2. Didier Deschamps
3. Walter Novellino
4. Alberto Zaccheroni
If Juve stay in A:
1. Didier Deschamps
2. Roberto Donadoni
3. Walter Novellino
5. Alberto Zaccheroni