I believe it’s protection from invaders because mountains are known as natural barriers and make invasions difficult due to having to climb up the mountains
I believe the answer is <span>Human Relations
</span><span>Human Relations is often used as the basic knowledge for employees development in modern companies.
</span>It help us analyze employees' behavior, self-development, and help the solve the problem/conflict that they experience in the workplace.
The 3rd one is correct I’m pretty sure