Respuesta :
The sentence that most adequately elaborates the author's suggestion through foreshadowing by the witches would be:
A). The author is hinting that good people will soon change to bad.
Foreshadowing
"Foreshadowing" is characterized as the literary device through which the author offers a hint or clue of the upcoming events in the narrative.
Through the given sentence, the author elaborates the witches' foreshadowing that 'Fair is foul...foul is air...filthy air' with the aim to suggest that even the noble people are likely to turn bad.
This hint makes the readers think about the approaching events and the consequences it will lead to when a good character turns evil.
Thus, option A is the correct answer.
Learn more about "Literary Device" here:
brainly.com/question/2183813