The correct answer is C) unrest and discomfort.
The kind of mood that Dante's line "sighs that caused the everlasting air to tremble" set is of "unrest and discomfort."
We are referring to the passage of the famous novel "The Divine Comedy," written by Italian writer Dante Alighieri, from 1308 to 1320. The passage is from Inferno, Canto 4, LIne 26, Circle 1, that says; "Here, for as much as hearing could discover, there was no outcry louder than the sights that caused the everlasting air to tremble."
The other options of the question were A) tranquility and peace. B) retribution and revenge. C) betrayal and punishment.