The correct option is A Tedious
Option B: The word 'fabulous' refers to something extraordinary or wonderful, for example, 'a fabulous vacation'. It's a positive word, but the sentence displays a contrast between two things. The conjunction 'whereas' refers to a contrast, and the words 'others have delightful jobs' is a positive aspect of the sentence. Hence to contrast with it, a word that has negative feelings attached, must be chosen.
So, option B is incorrect.
Option C: 'Unprofitable', in business terms, means 'not yielding profit or financial gain'. The sentence does not focus on the financial part. It focuses on the quality of the work (delightful jobs). Hence C is incorrect.
Option D: 'Indecent' means 'not appropriate or fitting'. This word, too, does not apply here, as it does not contrast with 'delightful'. Hence D is incorrect.
Option A: 'Tedious' refers to something dull and boring. It contrasts with something that is delightful and enjoyable. Hence this word is most suitable and option A is correct.