Mostly, the Europeans dominated because their numbers or military technology and organization were superior.
Considering the alternatives, the only alternative that represents any sort of military power being evolved with it is:
d. They built infrastructure to keep military units traveling and intimidating the locals.
Also, the British and other countries did build many railroads in Africa.
A reason could be that trading food wasn’t that popular at the time seeing that you only needed to grow food for your family
It helped people move and transport goods to other places
<span>They all believe in some kind of higher power. They also sometimes believe that their personal actions might judge whether they are rewarded, or punished by the higher power </span>deity(s)