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.
Should inornshould i not answer these questions for you? hmm.....
Sentence 3 is the answer because it shows specific evidence. While the other sentences just make claims, 3 is used to support sentence 1’s claim.
