Answer: Its not rare and this isn't a question so stop deleting my answer.
Fossil aren't the only cause of global warming. Many human activities are causing global warming. Most come from the combustion of fossil fuels in cars, factories and electricity production.
Hope this Helps!
I assume that the question refers to the political affiliation of the Islands (They are Islands in the Mariana Trench, in the Pacific Ocean, south of Japan) - they are politically linked to the US - the correct answer is a). For example the Mariana islands have a commonwealth status within the US.
