An important reason for China’s rapid population increase in the seventeenth and eighteenth centuries was: a: the introduction of new crops from the Americas
b: the end of the bubonic plague in Asia
c: the widespread adoption of the European three-field system
d: unprecedented immigration from the Mughal and Ottoman empires

d

Explanation:

presidency should be the title

the answer to fill in the blank in this question would be the word resource, it is defined as the money, material or people (since human resource is a very valuable good) that a company or a person has at disposition (meaning they can use the resource as they see fit), to be able to complete a task or achieve a goal.