The Most Significant Difference Between the Sociological Surveys of Today

The most significant difference between the sociological surveys of today and the "social surveys" conducted by early sociologists around the turn of the century lies in the:

A) bias built into early studies.
B) lack of generalizability of contemporary surveys to other groups and communities.
C) lack of generalizability of early surveys to other groups and communities.
D) statistical techniques that are used to analyze the data collected in contemporary surveys.