The author suggests that, before the early 1950's, most historians who studied preindustrial Europe did which of the following? A. Failed to make distinctions among members of the preindustrial European political and social elite. B. Used investigatory methods that were almost exclusively statistical in nature. C. Inaccurately estimated the influence of the preindustrial European political and social elite. D. Confined their work to a narrow range of the preindustrial European population. E. Tended to rely heavily on birth, marriage, and death records.