What events from "the black cat" seem to prove the wife's superstition about
cats to be correct?

The narrators wife voiced that all cats are witches this evokes the wife’s superstitious beliefs

Explanation:

The black cat is one of the stories which narrate the instability and the alcoholism of the narrator destroys his personality and his personal life. This is one of his dark tales and he explains how he killed his cat and wife because of his alcoholism.

His wife always believed the black cat as a sign of bad luck and she often describes it as witch. Later the author feels guilty about his act and then he regrets it

the answer is subjective. i personally agree with the first answer for this question.

if one isn't strictly talking about objects then the correct answer would be 'my eyes' since according to this riddle i am asleep and in order to answer/open the door i need to open my eyes first of all.

however, if one is specifically looking for an object, then the first thing i would open would be the door

hope this !