If P waves bend while entering the outer core what is the main reason?

Correct answer: Sudden difference in density and elasticity of medium

The direct answer is B: a sudden difference in the density and elasticity of the medium. P waves are seismic body waves. They travel through solid, liquid, and gas because they push and pull particles in the direction of travel. When a P wave reaches the boundary between the mantle and the outer core, the material changes greatly. Its density and elastic properties are different, so the wave speed changes. A wave changes direction when its speed changes across a boundary; this bending is called refraction. Step by step: first, the P wave travels through the mantle; second, it reaches the outer-core boundary; third, its speed changes because the material changes; fourth, its path bends. Option A is wrong because rainfall does not stop or bend deep earthquake waves. Option B is correct because density and elasticity control seismic-wave speed and refraction. Option C is wrong because surface wind affects air, not waves deep inside Earth. Option D is wrong because the Moon’s gravity does not suddenly end and is not the main cause of this seismic bending. The shadow-zone pattern is related to refraction and changes in wave speed. Memory cue: a change of material causes a change of speed, and a change of speed causes bending.