Can you ! a lot of points

why does gravity cause erosion?

not how but why

Gravity is responsible for erosion by flowing water and glaciers. That's because gravity pulls water and ice downhill. These are ways gravity causes erosion indirectly. Gravity can pull soil, mud, and rocks

When materials like rocks and soil on the Earth's surface wear down to sand and gravel or move from one location to another, erosion is the main culprit. ... But the most powerful force behind erosion is gravity. Gravity causes chunks of rock to fall from mountains and pulls glaciers downhill, cutting through solid stone.

i do not know if this will help you because there is not a lot a lot of research, specifically explaining why gravity causes erosion.

good luck!

answer; (b); i believe its indefinite existence of human population in a healthy and prosperous condition;