The auroras occur in the
a. troposphere
c. mesophere
b. stratosphere
d. ionosphere

d. ionosphere

Explanation:

The auroras are caused by the sun, the energy and particles that reach us from the sun are trapped in the earth's magnetic field, which causes the auroras that we see in the Earth's poles.

The auroras are produced in the layer called ionosphere, here there are gases that interact with the particles of the solar wind trapped in the magnetc field, the different colors of auroras such as red, green, blue or violet are the result of the different gases that exist in the ionosphere.

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.