Answer:
a. Paul Lazarsfeld
Explanation:
Paul Lazarsfeld -
He was the founder of the Columbia University's Bureau of Applied Social Research .
Paul Lazarsfeld was a very famous Austrian-American sociologist .
He started the use of various techniques and organization of the social research .
He contributed most to the challenge mass society theory and encourages the development of the scientific theories about the mass communication .
Hence , from the given information of the question ,
The correct answer is a. Paul Lazarsfeld .
