In the passage, the author is primarily concerned with doing which one of the following? A. identifying an assumption common to various assimilationist theories and then criticizing these theories by showing this assumption to be false B. arguing that the recent revival of a number of tribal practices shows sociologists are mistaken in believing intertribilism to be a potent force among native American societies C. questioning the belief that native American societies will eventually be assimilated into Euroamerican society by arguing that intertribalism helps strengthen native American identity D. showing how the recent resurgence of tribal activities is a deliberate attempt to counteract the growing influence of intertribalism E. proposing an explanation of why the ascension of intertribalism could result in the eventual dissolution of tribes and complete assimilation of native American into Euroamerican society