Answer : The inner core and the inhomogeneous mantle.
Explanation : The inner core and the inhomogeneous mantle present in the Earth's interior, are the parts that causes the diffraction of P waves made by earthquakes. The name P-wave may have abbreviated form for either pressure wave (as it consists of compressions and rarefactions) or the primary wave (because of high velocity and first wave to be recorded by a seismograph).
<span>The Core and an inhomogeneous Mantle cause diffraction of P-waves. </span>P-waves<span> are a type of elastic seismic wave </span><span>that travel through a continuum and are the first </span>waves<span> from an earthquake to arrive at a seismograph.</span>
