The correct option is D magnum opus
Option D is the correct answer because “magnum opus’ means a work of art, music, or literature that is regarded as the most important or best work that an artist, composer, or writer has produced, hence it is correct.
Option A is incorrect because “par excellence” means better than all the others of the same kind, which is incorrect because here literary, work and art is being mentioned, if it was only one, it would be correct.
Option B is incorrect because “bête noire “ means a thing or a person that one particularly dislikes, which is not in context with the statement.
Option C is incorrect because “peccadillo” means a fault or a sin committed.