Geometric boundaries are especially common in A.
former colonies, because geometric boundaries can be negotiated without traveling to the location.

B.
non-self-governing territories, because geometric boundaries can effectively reinforce cultural boundaries.

C.
island states, because geometric boundaries can effectively reinforce physical boundaries.

D.
states bordering rivers, because rivers tend to shift their courses slightly over time, requiring oversight.

E.
regions with impassable mountain ranges, because this inaccessibility makes them poor boundaries.

the correct answer is c

it is very hard for the climatologists to precisely predict how will the global temperatures be changing so there's lots of models, some of which differ significantly, this is due to multiple factors, and probably the most important is the human activity.

humans have been a key factor in climate change around the globe since the start of the industrial revolution, and in the past few decades the consequences are becoming more obvious. there's lots of emission of pollutants in the atmosphere as well as changing the environment on the surface itself, so it's really hard to predict how will that go in the future because there's some countries that are reducing the damage and are going towards green energy, while others are stubbornly continuing with pollution and damages to the environment.