Ummm I need help pls.. HELP

Subduction zones occur on earth where dense oceanic crust dives under more buoyant continental crust. these boundaries are characterized by a deep ocean trench next to a high continental mountain range, large numbers of earthquakes and volcanoes. all of this is further evidence for the a) big bang theory b) origin of the species eliminate c theory of plate tectonics d theory of natural selection 4 sedimentary rocks found high in the himalayen mountain

Analyze how limestone is weathered and identify the features that are formed as a result of this dissolution

Hey guys so i need to know what is _nh3+> nh4oh ~chemistry~