Define the concept of inertia.
a. the property of an object to change its energy.
b. the property of an object to keep moving at its current speed and in its current direction.
c. the property of an object to have its motion changed by an outside force.
d. the property of an object to experience the same force it applies to another object.

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.

third one with arrows on top of each other going the same direction