What Happened During the Warring States Period of the Eastern

What happened during the Warring States period of the Eastern Zhou dynasty?

A) The territorial states sought to maintain a balance of power and would re-form coalitions if one state became too powerful.
B) The Zhou king lost all formal authority over the territorial states.
C) The warfare among the territorial states remained small in comparison with that in Southwest Asia.
D) Power became concentrated in the major states' rulers.