B. Exploration and description- Early Colonial period. This is one of the earliest approaches in the history of human geography. It involves early explorations and descriptions of different regions and peoples.

D. Regional analysis-Later Colonial period. Regional analysis is an approach that became more structured and prominent as human geography developed. It involves the systematic study of regions and their characteristics.

A. Areal differentiation- 1930s through the inter-War period. Areal differentiation, which involves the study of spatial patterns and regional differences, emerged as human geography evolved.

C. Post-modernism in geography- 1990s. Post-modernism is a relatively recent development in human geography, emerging as a critical and reflexive approach to challenge existing paradigms and examine the complexities of contemporary spatial relationships.