Final answer:
The transition from acephalous bands and tribes to chiefdoms began around the second century AD when some chiefs in Japan formed statelets along the Kyushu coast.
Step-by-step explanation:
The transition from acephalous bands and tribes to chiefdoms began around the second century AD. In Japan, some chiefs formed statelets along the Kyushu coast and claimed predominance over their neighbors. They acquired and made bronze daggers and mirrors to establish their authority. This transition occurred when the clans faced climate changes and trade routes were established.