I have not looked too much into their schedules, but Ohio State has the better loss between the two. And off the top of my head it seems Oklahoma has more quality wins.
As BYU fans I guess we are rooting for an 11-1 Ohio State to be picked over an 11-1 Oklahoma assuming Michigan State, Alabama, and Clemson are the other three teams. Rooting for Ohio State to make the CFP feels kind of dirty.