When developing plot, of what element should a writer have a clear understanding before the beginning?

The exposition

The conflict

The climax

The resolution

The Exposition i think

Well I would say All of the above cause you should have an understanding of everything when developing a plot to a story but I would basically say the conflict like whats going to happen in the story and whats going to happen to a character to change there state of mind of whats going on and etc.