Rearranging the sentence and trying to grasp the meaning of what we do have here, based on logic
We do have a Requiem, which is basically a eulogy of a passed person, that is ONE OF THE MOST - that means the works is quite good and we have to have a word to sustain the MOST. Therefore the answer is C
Now, one of these most famous works is incomplete at the time Mozart passed away. Because Mozart was a genius and because the works is incomplete, the work itself has a sort of aura, of mystery, something arcane that we are not able to understand completely or decipher
E is completely off. D is a bit tricky but the meaning of the sentence is that the work is yes obscure but is a sense that has a fascination to it. It is enthralling. So F is the correct word.
For the third black many buzzes arose around it. Again, we are not sure 100% of the stories behind this work and how it came to us on the present days, and because the truth is lost neither fraudulent is the correct choice nor verified. We do not have both of them likely scenario
H is the last correct blank. which is also means: the work has not a signature. We do not know for sure who wrote it.
I hope this helps
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