In The Lamb to the Slaughter, the exposition is when it tells you that Mary is in love with Patrick and is pregnant with his child. Patrick is acting differently around Mary though.
Climax
In Lamb to the Slaughter, the conflict is that Patrick is acting differently around Mary and wants to divorce Mary but they are having a kid together.
Falling Action
In Lamb to the Slaughter, the action of the story begins to rise when Patrick comes a home and tells Mary how he is feeling and that he wants to divorce her.
Resolution
Did we eat the weapon?
In Lamb to the Slaughter, the climax is that Mary attacks Patrick with a lambs leg and kills Patrick.
In Lamb to the Slaughter, the falling action is when the police tried to solve the mystery of who killed Patrick but then they eat the weapon that was used to kill Patrick.
In Lamb to the Slaughter, the resolution is that the police started to figure out that the lamb leg was used to kill Patrick