Trying to move a door from one place to another. Trouble is that,
despite all of the doorways notionally accommodating a 78 x 30 door, one
is obviously a tiny bit wider.

What would you do - I can only think of;

A) trying to fix an additional piece of timber (about 5mm thick) down
the hinge side of the door to make it wider and start again. Though it
may make the door look a bit odd.

B) Fix a similar piece of timeber on the inside of the door frame to
narrow the gap - althought this would not leave much of the jamb
visible. Advantage is that I'd be able to paint over this (the door
itself is natural wood).

Is there a right way ?

Thanks