The answer is B: Economics.
Explanation for each option:
(A) Astrology: Astrology is not a topic of study in early sociology. Sociology focuses on the study of society, social institutions, and social relationships, whereas astrology is concerned with the positions and movements of celestial bodies and their supposed influence on human affairs.
(B) Economics: Economics was indeed a topic of study in early sociology. Early sociologists like Karl Marx and Max Weber examined economic systems and their impact on society. They explored how economic structures influence social relationships, class dynamics, and societal development.
(C) Physics: Physics is a natural science that deals with the study of matter, energy, and the fundamental forces of nature. It is not a topic of study in sociology, which is concerned with social phenomena rather than physical phenomena.
(D) History: While history is related to sociology in that both disciplines study human societies, history focuses on past events and their chronological development. Sociology, on the other hand, often examines contemporary social structures and patterns. However, historical context is important in sociological studies to understand the evolution of societies. Nonetheless, history itself is not a primary topic of study in early sociology.