Which best explains how gravity contributes to the formation of layers in protoplanets? Gravity attracts materials and causes compaction, which produces heat and leads to the melting, sinking, and rising of materials. Gravity causes materials to undergo radioactive decay, which produces heat and leads to the melting, sinking, and rising of materials. Gravity absorbs heat, which cools materials and causes them to sink and rise. Gravity releases heat into space, which cools materials and causes them to sink and rise.

A

Explanation:

i think that c)gold was found there

but i am not sure

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.