Based on the description provided, early settlers would most likely choose location B as the best place to establish a settlement. Location B is in a patch of dark green near a body of water, which suggests proximity to resources such as fish from the water and potentially fertile land for farming compared to the other locations.
Locations A and D are in green and tan, respectively, which are further from the water and less favorable for both fishing and farming. Location C, while in a large expanse of tan, is also further from water sources.
Therefore, the best choice for settlers would be B.