Final answer:
The Mississippi River's division of Minneapolis and St. Paul is a d) natural boundary, as natural geographic features commonly dictate political borders of regions. Rivers, mountains, and lakes are often used as borders, exemplified by historical boundaries such as the Rio Grande and the Great Lakes.
Step-by-step explanation:
Natural physical geographic features often determine the political boundaries of formal regions, such as cities, states, or countries. Looking at maps, it is evident that many political boundaries coincide with natural features like rivers, mountain ranges, and large lakes, which serve as clear and often indisputable dividers of land into separate political units.
Historical examples include the Rio Grande, which serves as a portion of the border between the United States and Mexico, and the Saint Lawrence Seaway alongside the Great Lakes, which mark parts of the border between Canada and the United States. In Europe, the alpine mountain ranges create natural borders, such as the one between Switzerland and Italy.
Therefore, in the context of Minneapolis and St. Paul, the Mississippi River provides a clear dividing line between the two cities, which is a natural occurrence rather than a man-made demarcation. This is aligned with the concept expressed in the standards WG.13A, which involves interpreting maps to explain the division of land, including the identification of natural borders like rivers. The division of the cities in Minneapolis and St. Paul by the Mississippi River is an example of a d) natural boundary.