I believe the answer is: Stop
The message 'stop !!' is usually used in a distressful situation where it is necessary to grab the attention of people near you.
For most people, it is easy to get the attention because our voice tend to rise in volume when we say 'stop'. For those who use hand signal, the sign must be really obvious and easy to understand by other people near them.
The fourth one, voluntary exchange
Answer:
Yes, it has always been relevant.
Explanation:
You would get one of your libs chopped off
be humiliated
be tortured
and killed
Answer: unnecessary items
Explanation:
Like toys or games or electronics