Just little ol me talking here,but I think the rook to move is F1. The F2 pawn isn't going to move for a while,whereas the queenside pawns can move forward to gain space in that area. So A1 rook stays or moves to B1 to support that expansion.
My rating isn't very high so this may be all wrong,but it is what I think about which rook to move.
Frequently I run into this situation where I have a choice of rooks to use in occupying an open file. I'd appreciate any comments people have about which rook they would choose and why. My move in this game was, after much uncertain deliberation, to move Rf-d1.