It isn't the SEC?
Ranked SEC teams:
South Carolina (13)
Other SEC teams that have been in the Top 25 (Georgia/Florida/Ole Miss)
It is inevitable that some will fall out of the top 25 because they have to play each other.
For example, take my Vols schedule this year.
Alabama (1) On the road
Oregon (2) On the road
Georgia (6 at time of game)
Florida (19 at time of game) On the road
South Carolina (11 at game time)
Missouri (9) On the road
So 5 games with opponents in the top 10, three of them on the road (Alabama/Oregon/Missouri)
Two more ranked opponents, one of them on the road as well.
They had a brutal schedule this year and only one of those teams isn't in the SEC.