This statement is false. There is actually five types of plains. The five types of plains are coastal plain, alluvial plain, glacial plain, terrestrial plain and flood plain. Plains are flat areas that are usually located in lowlands and at the bottom of the valleys.
Yes, as the earth gets closer it gets warmer and as the sun gets further it gets colder
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.