I need help please Which of the following could describe how a metamorphic rock eventually forms?

A) Layers of mud build up and turn to solid rock over time.

B) A volcanic lava flow cools and hardens on the surface.

C) A river carries sand and piles it up in the bottom of a lake.

D) Two large pieces of land slowly smash into each other.

Waste water from industries and domestic sources can be treated by chlorination or ultraviolet radiation. there are pros and cons to using either chlorine or uv radiation to kill harmful microorganisms. what is one reason chlorination would be preferred over ultraviolet radiation? a) chlorine only eliminates visible impurities and is ineffective against microorganisms. b) chlorine not only kills bacteria but provides a residual effect on returning microorganisms. c) uv radiation can be used only to treat drinking water and is ineffective in treating waste water. d) ultraviolet radiation is more effective