Where to relocate a bomb on a plane to minimize damage?
We covered that stuff during recurrent training and for the CRJ Regional Jets we were told to place it in the forward galley in front of the service door (opposite the main door) and cover with with as much weighty stuff as possible, wet blankets, heavy coats, and such.  

You had the mass of the galley to protect the flight deck to some degree, and in theory the explosion would blow out the service door, hopefully leaving the structural frame surround intact, so that overall, it would have the least impact structurally for the fuselage as a load bearing tube with the peak stress just ahead and behind the wings.

In theory... nobody actually believed it would save the plane unless it was fairly small device, but as a calculated strategy to make the best of a hopeless situation, it made sense.

Don't know about other jets, but I would expect that the overall logic is similar.