A. Early colonial (III. Exploration and description): During the early colonial period, one of the primary approaches in human geography was the exploration and description of new territories and regions. 

B. 1930s Inter-war (IV. Spatial organization, Areal differentiation): In the 1930s, the inter-war period saw a significant emphasis on understanding the spatial organization of human activities and the differentiation of various areas based on their unique characteristics. Geographers during this time analyzed the spatial distribution of human populations, economic activities, and cultural patterns, contributing to a more nuanced understanding of regional differences.

C. 1950s and 60s (I. Post-modernism): In the 1950s and 60s, the post-modernism approach gained prominence in human geography. This approach called into question the traditional assumptions and methodologies in the field, emphasizing the subjective nature of knowledge and the importance of considering multiple perspectives. 

D. 1990s (II. Period): In the 1990s, the focus of human geography shifted towards understanding the impacts of globalization and technological advancements on human interactions and spatial dynamics. 

So, answer would be 3. A-III, B-IV, C-I, D-II