Which of the following statements best describes the role of the caste system in india today?

At a continent-continent convergence,

Religious conflict in northern ireland started with a) cultural differences resulting from viking invasions around 800 b) england’s split from the catholic church in the 1500s c) rebellions in ireland between 1916 and 1921 d) the norman invasion of england in 1066

Plzz on what physical process is responsible for the creation of volcanoes, earthquakes and ocean trenches at the plate margins?