The answer is c - surrounded by mountains
Where an increasing proportion of the workforce has a university degree, the value of basic skills in literacy and numeracy remains high. Indeed, in some countries the return for such skills, in the form of higher wages, is sufficiently large to suggest that they are in high demand and that there is a relative scarcity. Policymakers need robust evidence in order to devise interventions that genuinely improve basic skills, not just of new school leavers entering the market, but also of the existing workforce. This would lead to significant improvements in the population that achieves a minimum level of literacy and numeracy.
The correct answer is B) As a way to transport goods and people.
Rivers were important to people migrating west "As a way to transport goods and people."
With the Westward expansion, the American people started to settle in the western portion of the territory. Rivers played a major role in the exánsion because they served As a way to transport goods and people.
Let's have in mind that US President Thomas Jefferson had ordered the purchase of the Louisiana Territory owned by the French. So in 1803, after the purchase, Thomas Jefferson ordered the Lewis & Clark expedition to explore the western territories. The Expedition lasted 3 years. After that time President Jefferson was briefed about the findings and that is when he authorized the westward expansion.