Site finishing issues.

I have a doorway where the 2.25" red oak currently goes from a first room into the doorway (in between and perpendicular to the doorway) and ends at the adjoining second room, where I am to install 2.25" red oak perpendicular to the first room. First room is already sanded and finished with exception of the last inch or so, (inbetween the door jambs) right where I need to lay my first board perpendicular in the new room. In this 1 inch section (the end of the boards), is cutback adhesive. I have a few options, and was wondering what someone would suggest.

a. Sand the last inch (cutback adhesive) of the first room inbetween the door jambs, and "blend" the poly with the new boards that will be perpendicular to it. I think this will be noticable.
b. Cover the last inch with a threshold (t-molding)
c. Cut out 2.25" of the ends of the boards (in between the door jambs) and place one or more new red oak boards.
d. any other ideas?

Your thoughts are appreciated.