One of the Significant Characteristics of Russia, Which Differed Dramatically

One of the significant characteristics of Russia, which differed dramatically from the West, was Ivan III's use of ______________.

A) permanent legalized serfdom
B) an aggressive tax campaign that exhausted the financial resources of his subjects
C) tying peasants to the land to force landlords to stay where they were rather than move to the frontier
D) creating a standing army in exchange for land after twenty-five years of service
E) creating a permanent military servitor class