Answer:
Coastal enclaves for trade and a few settlements
Step-by-step explanation:
Before 1870, the European presence in Africa was characterized primarily by "Coastal enclaves for trade and a few settlements."
This is evident in the fact that before the 1870s, most Europeans are only in Africa for the transatlantic slave trade. Thereby, they mostly settle near the ocean where they can easily and quickly transport the people they bought into slavery to the European and American continent.