What is the definition of opportunity cost? 1-4 which one is the correct answer

1. Opportunity cost refers to a NEGATIVE effect that a person could experience but gave up to take another course of action

2. Opportunity cost refer to a BENEFIT that a person could have received but gave up to take another course of action

3. Opportunity cost is a negative effect for a decision made

4. Opportunity cost is a benefit that a person received before taking another course of action