Answer: It indicates that wagon consisting the letter X is the last wagon of the train. It easily alerts the railway officials so that they can save from the accident.
Explanation:
It may be C I'm not exactly sure
It’s B as the answer choice
If you mean where they are kept, then I am pretty sure it is in the Smithsonian, but like I said, I don't know for sure, but I am pretty sure. If it is wrong I am sorry, but if it is right then YAY! Also, goodluck on your quiz or whatever your doing!
