D, yes it is worth keeping it as a flanker. Hubbard not having a full set of stations in the market is hurting them in market billing. (96.9 & 97.1 count as 1 each preventing them from getting another one). Leasing this one out will drag them down even more.
I can't calculate what GK is getting in return, paying for an HD2 signal nearly no one will listen to. Hubbard is adding on to their revenue every month renting it.