12. Which of these describes the gravitational force from a planet?"
O
large and pulls objects toward itself
small and pulls objects toward itself
O
small and pushes objects away from itself
O
large and pushes objects away from itself

A. Large and pulls objects towards itself

Explanation:

Think about when you jump, you push yourself off the ground then gravity pulls you back down.

That takes out those last two answers.

Now let's think, is our planet large or small?

That's right, our planet is large.

So now we know the answer is the first one

layer a is the exosphere and layer b is the thermosphere.   is the answer i think but i hope this .