Mohorovicic observed that earthquake waves were moving faster when recorded farther away than 200 km from where the earthquake started, known as the P waves. This characterisitic is due to (1 point)
a change in speed because of the decreased density of the mantle.
an increased wavelength of the seismic energy wave.
a change in speed because of the increased density of the mantle.
an error when he read the seismograph read out.