Justifiable defense refers to a limited act against an unlawful trespasser in order to protect the state, public interest, personal, property and other rights of himself or others from ongoing unlawful infringement.
According to the above definition, which of the following belongs to justifiable defense?
A robbed B with a knife, B fought back and grabbed A's knife, and stabbed A in the leg, A could not move, and then B killed A with a knife