Analyze Knights-and-Knaves Dialogue Variants

On an island where every person is either a knight (always tells the truth) or a knave (always lies), you meet two people, A and B. Person B says to A: "You always lie," and then makes one additional claim chosen from exactly one of the following four variants: 1) "A is a knave and B is a knight." 2) "A is a knight and B is a knave." 3) "A is a knave and B is a knave." 4) "A is a knight and B is a knight." For each variant independently, determine the logically consistent identities of A and B (knight or knave), or conclude that the information is insufficient or inconsistent. Show your reasoning.