Which statement is most accurate? a- the greater the physical density of a material, the higher the refractive index. b- the greater the optical density of the material, the lower the refractive index. c- the more optically dense the material, the higher the refractive index. d- the greater the physical density of a material, the lower the refractive index.

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.

the maxium height is 34m/s