The correct answer is C. River Valleys.
Step-by-step explanation
The first human settlements were next to the river valleys due to the importance that water had (and still has) in the lives of humans, this natural resource was too important for humans because it allowed them to hydrate and made the soil fertile for agriculture, that is to say that it allowed societies to have plants that provided them with fruits for their food, besides water was an important resource for grazing animals such as sheep, cows, deer among others. So, the correct answer is C. River Valleys.