Explain how metamorphic rocks are formed, and explain the differences between regional and contact metamorphism?

Metamorphic rocks form when pre-existing or parent rocks (whether igneous, sedimentary, or even metamorphic) are altered by heat, pressure, and the chemical activity of fluids. When the dominant altering factor is heat, usually  from direct contact , it may undergo fundamental change  in texture and recrystallization is called contact metamorphism. While regional metamorphism,  where rocks texture and minerals are changed by heat and pressure.

Your answer is c. explanation: plasma  is the fourth state of matter, derived from the gaseous state of matter.  plasma  can contain free  electrons  and/or  ions. while  plasma is never neutral, it can either be positively or negatively charged.  gases, however, are electrically neutral.