Which option gives the most scientific reason for pressure increase inside Earth?

Correct answer: Weight of overlying rocks and materials increases with depth

The direct answer is A. Pressure inside Earth is mainly caused by the weight of material lying above a particular point. As depth increases, more rocks and other matter press downward on the material below. The overlying load, or overburden, therefore becomes greater, and pressure generally increases toward the centre. High temperature also affects the state and behaviour of deep materials, but it is not the basic reason given in this question for pressure increase. Option A is correct because it identifies the increasing weight of overlying rocks and materials. Option B is wrong because sunlight does not travel directly to the core and does not create the internal pressure. Option C is wrong because ocean water cannot flow through the solid Earth to the centre. Option D is wrong because the atmosphere is only a thin outer layer; its weight is tiny compared with the enormous load of rocks above deep regions. A useful chain is: greater depth → more overlying material → greater load → greater pressure. Memory cue: “pressure comes from overburden.”