From what i know it is c. it is a lever
The three main layers are the core, the mantle, and the crust. The core is divided into two parts, the liquid outer core, and the solid inner core. Together it is 3450 km thick. The mantle is 2100 km thick, and the crust is 35-70 km thick. Hope I helped!
First one, holding a basketball in the air. Potential energy is the energy it has mostly from gravity. The further you go from the center of mass, the more energy.