Final answer:
The correct answer is option b. Elizabeth decides to wait until Longbourn to discuss Darcy's proposal with Jane because she values privacy when discussing sensitive topics and wants to observe Jane's reaction in a comfortable setting.
Step-by-step explanation:
The passage about Elizabeth's decision to wait until reaching Longbourn to tell Jane about Darcy's proposal holds hints suggesting that the correct answer is B) She is unsure of how Jane will react and wants to gauge her emotions in private. Throughout Jane Austen's novel, Elizabeth values Jane's opinions highly and the private nature of their conversations often leads to sincere and open discussions of their feelings.
Additionally, the privacy of Longbourn provides a comfortable environment where Elizabeth can discuss serious matters and see Jane's reaction directly, without the distress of travel or eavesdropping strangers.