Write a question about the following article.

This differential only has a little over 150 miles on it . I bought this unit used from a fellow with a Mustang who had it in his car but ended up pulling it for an E - locker for manual lock control . This diff is in great shape . Auburn makes a very solid LSD that will take a beating and not wear out for a long time .

Question:
What is the narrator inspecting ?
Choose your answer from:
(1). They are looking at horses .;
(2). They are looking at automobiles .;
(3). They are looking at mustang ponies .;
(4). They are looking at animals .;