Final answer:
The correct answer is option 2. Macduff's use of 'one fell swoop' illustrates his shock and devastation from losing his entire family in a sudden, tragic act.
Step-by-step explanation:
The idiom "one fell swoop" used by Macduff in Macbeth emphasizes the sudden and complete nature of the tragic event, where Macduff's family was killed. When Macduff uses the term to describe the murder of his 'pretty chickens and their dam,' he is expressing the shock and devastation that his entire family was taken from him in a single, swift action.
This confirms that Option 2 is the correct interpretation: Macduff has lost his entire family at once. This reveals the depth of his loss and the cruelty of the act, as he likens his innocent family to helpless chicks and their mother killed in one merciless act by Macbeth's command, whom he refers to as a 'hell-kite,' symbolizing evil and predation.