The correct options are B
Option A - 'Extant' is used to refer to something that is very old and is still existing. Thus option A is incorrect.
Option D - 'Nervous' means worried and anxious. Thus option D is incorrect.
Option B - 'Obsolete' means something that is not in use anymore. Thus option B is the correct answer.
Option C - 'Out-dated' is used to refer to things that are no longer in use and have been replaced by better things. Thus option C is the correct answer.
'A word no longer in use - Obsolete / Out-dated'