Which of these best explains why earth’s inner core is a solid? low pressure due to other layers forces the particles to stay closer. high pressure due to other layers forces the particles to stay closer. high temperature due to other layers keeps the particles close together. low temperature due to other layers keeps the particles close together.

I believe the answer is high pressure due to other layers forces the particles to stay close together. It can’t be the first option because no pressure would let them act as they want to. It can’t be the third option because heat will cause the particles to move much more than they would in cold temperature. It could be the last option since cold keeps particles still but the temperature inside the earth is quite hot so the inner core wouldn’t be cold. I hope this helps!