The answer is A. European leaders were concerned about instilling good hygiene practices.
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Han in the Xiongnu were several of the battles from "133 BC to 89 AD". During the reign of the WU emperor where the Han Chinese won over the Xiongnu, before these battles the Xiongnu were a nomadic group that reigned in modern Mongolia.
During these battles political instability was generated, producing that the state of Xiongnu was divided in 2 parts and had crisis of successions, having massive revelations between its towns the Wusun, Wuhuan and Dingling.
In 60 BC Han China established the protectorate in the western regions beginning the decline of the Xiongnu reign.
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