Leopold Claims That History Has Shown That "The Conqueror Role

Leopold claims that history has shown that "the conqueror role is eventually self-defeating." It is self-defeating, in this view, because

A) the conqueror doesn't understand what makes the conquered community tick.
B) the conqueror doesn't know what and who within the community is valuable.
C) the conqueror doesn't know what and who is worthless in community life.
D) all of the above