Proofread the sentences. which word is spelled incorrectly? in the vestibule below was a letter-box into which no letter would go, and an electric button from which no mortal finger could coax a ring. it was well perhaps that life thus early gave me a hint of one of her most obstenate and insoluble riddles. his arguments are well thought-out and almost irrefutable, and he comes up with them instantaneously. secret operations of government espionage go back to the beginnings of the united states.

The word that is spelled incorrectly is "obstenete". The correct spelling is "obstinate".

The word 'obstinate' is an adjective mainly used to refer to someone or something that is difficult to deal with. In this case, 'obstinate', which has been spelled incorrectly, is modifying the noun 'riddles'; therefore, it is describing the riddles as difficult to solve and to overcome. Synonyms of this word are intractable, indomitable and unconquerable. The correct way of spelling it is with an "i" after the first "t" and an "a" after "n".

i think it may be b, i'm not exactly too sure on this. but b seems to make more sense.

i may be wrong but i think your answer is flashback