Which topic is most closely related to the study of culture as part of human geography

Cultural geography is a subfield within human geography. Though the first traces of the study of different nations and cultures on Earth can be dated back to ancient geographers such as Ptolemy or Strabo, cultural geography as academic study firstly emerged as an alternative to the environmental determinist theories of the early 20th century.
As a result, cultural geography was long dominated by American writers.

The answer would be b.

Ithink it's a. but i could be wrong because it might be b. but it's not the other two