Final answer:
It is debatable whether Genghis Khan killed over 30% of the population; while his campaigns caused high mortality in certain regions, global estimates are speculative.
Option A.
Step-by-step explanation:
The claim that Genghis Khan killed more than 30% of the population at that time is historically debatable.
While it is true that Genghis Khan and the Mongols were responsible for widespread destruction and high mortality rates in the regions they conquered, estimating the exact percentage of the global population that perished is challenging.
The depictions of Mongol conquests often speak to high mortality in cities such as Kaifeng, where mortality seemed to be at least 40%, but spreading this figure across the entire population affected by the Mongol Empire is speculative.
Beyond the brutality, Genghis Khan also established legal and institutional frameworks aimed at societal stability within the Mongol Empire.