Which is the best explanation for why the subjective mood is used ?

1.Sometimes you are making a request or asking something
2. Often you need to make a definitive statement
3. There are times when you do know a situation will turn out
4. In some cases you need to express a wish or desire

4. In some cases you need to express a wish or desire

The subjective mood is often used to communicate desires, wishes, or hypothetical situations that may not actually be true. It allows the speaker to express their thoughts and feelings in a more nuanced and emotional way.