The events A and B are not mutually exclusive, since there is one card (the king of clubs) that satisfies both conditions (i.e., it is both a club and a king).
In general, two events are mutually exclusive if they cannot both occur at the same time, meaning that there is no overlap between them. In this case, since there is one card that is both a club and a king, the events A and B are not mutually exclusive.