Human geographer would most likely study . a.
changes in the size of the Antarctic icecaps
b.
the housing styles of the Baka people of the Congo
c.
the landforms of the American Southwest
d.
earthquake patterns in the South Pacific

I would say b.  the housing styles of the Baka people of the Congo

Explanation: I said this becuase a human geographer does the study of the interrelationships between people, place, and environment, and how these vary spatially and temporally across and between locations.