Do you have more of an idea other than just ancient castles?
Answer: their
Explanation: The sentence is addressing car buyers having something, in this instance a choice. When the subject is possessive, you use their. Such as, the car buyers ate <em>their</em> lunch.
I believe the correct answer is A. She does not want to be deceived.
During the long years that Penelope waited for her husband Odysseus to come home, many people have come to Ithaca pretending to be Odysseus. So she is not likely to believe anyone that easily when they present themselves as her husband, which is why she is cautious even around the real Odysseus.