Respuesta :
The lines that show that Macbeth is on the verge of giving in to temptation, knowing very well that he is considering committing a terrible crime are:
"Macbeth wonders to himself whether all the prophecies will come true". He knows that in order to become King, he has to commit a terrible crime, killing his cousin Duncan and he is thinking of doing this.
Answer:
The correct answer is "if ill, Why hath it given me earnest of success, Commencing in a truth?"
In this part of Macbeth's monologue we can see Macbeth's doubt and uncertainty. He wonders why would the witches lie after telling him the truth. He starts to believe that the second profecy, just like the first one, will come true, and thus starts to consider about commiting the horrible crime that would be necessary for that to occur.