Answer
Either Person A is a knight and Person B is a knave, or Person A is a knave and Person B is a knight.
Work Step by Step
Person A says "I am a knave or person B is a knight" and person B says nothing. Person B's silence gives no information as to whether she is a knight or knave.
If person A is a knave, the first half of the statement is true so the second half must be a lie. Thus, person B is a knave as well.
If person A is a knight, the first half of the statement is untrue so the second half must be true. Thus, person A can be a knight if person B is a knave.
