It is whom. You can only use who if you can replace is with he or she.
Answer:
Ever since the beginning of history, sage Emperors and wise rulers have bestowed on china a moral system and inculcated a code.
Our celestial Empire possesses all the things in prolific abundance and lacks no product within its own borders,
Moreover, our dynasty, swaying the myriad races of the globe, extends the same benevolence towards all.
Explanation:
90% sure it's D. And I have to make this answer long or else I can't submit it so that's why I added this whole sentence
