“...it was this deficiency, perhaps, of collateral issue, and the consequent undeviating transmission, from sire to son, of the patrimony with the name, which had, at length, so identified the two as to merge the original title of the estate in the quaint and equivocal appellation of the “House of Usher”” Edgar Allan Poe. The Fall of the House of Usher.

Using context clues, which is the best definition of undeviating?

unjustly inflicting hardship and constraint
very sad
something that you can barely stand
unchanged