Final answer:
Lady Macbeth's line "Nought's had, all's spent, Where our desire is got without content," reflects the emptiness of gaining the throne without happiness, as she and Macbeth live in fear, making option b the correct answer.
Step-by-step explanation:
In The Tragedy of Macbeth, Act III, when Lady Macbeth says, "Nought’s had, all’s spent, Where our desire is got without content," she is expressing the futility and emptiness of their actions. Despite achieving the throne, Lady Macbeth and her husband have found no joy or peace because they are plagued by guilt and fear. The correct answer to the student's question is option b. She and Macbeth have risked everything but have gained no happiness because they are living in fear. This line encapsulates the moral of the play that ill-gotten gains never yield true happiness and foreshadows the downfall that both characters will eventually face.