Evidence to Support That the Inner Core Is Solid and the Outer

Multiple Choice

Evidence to support that the inner core is solid and the outer core is liquid comes from

A) refraction of seismic waves as they encounter different mediums.
B) the wave shadow effect of P- and S-waves as they encounter the solid and liquid core.
C) the wave shadow effect of P- and S-waves,and the increase in velocity of P-waves as they encounter the solid inner core.
D) the inner core is not solid,but is liquid.