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
Opportunity cost refers to a benefit that a person could have received, but gave up, to take another course of action. Stated differently, an opportunity cost represents an alternative given up when a decision is made. This cost is, therefore, most relevant for two mutually exclusive events.
So the answer is B. what you give up when you choose one thing insisted of an another
If this helped pls mark as brainliest thx
The common core ........................
Republic means the head of the state is an elected person
