I think it is B <span> By allowing more labor unions</span>
Tropical hunters & gatherers
<span>The zone of proximal development is a range of tasks that a child cannot yet handle alone but can do with the help of more skilled partners.</span>
The practice in Medieval Europe was most similar to a Japanese warriors code of Bushido is chivalry. Chivalry is a code of conduct of the knighthood which was developed between 1170 and 1220. This came from the Roman Empire from the ideas of cavalryman.