What is a portion of a country that is separated geographically from the mainland

Lines of longitude are like stripes from the top of the globe down to the bottom virtually slicing the earth like an orange

What did the pattern of earthquakes in the wadati-benioff seafloor zones show scientists? a.) earthquakes occur where the ocean floor reaches its highest temperatures. b.) many earthquakes take place 700 kilometers below the seafloor. c.) slabs of ocean floor return to the mantle in subduction zones. d.) ocean - trenches cause earthquakes.

Can someone me with this plz? ! i'm putting 20 points on it!