The correct answer is B.
It helps illustrate changes in landforms over time and it shows the impact of human habitation on an area: We are able to compare two different images from the same area in a particular place on earth to compare them and understand how this specific place changed over time. Geographers are able to recognize the widespread changes to an area with views from satellite imagery.
the pastoralists were in the Maasai tribe
If I'm not mistaken, I believe that they're called Sea Dogs
