Answer:
The best phrase which supports the eruption would be high-viscosity magma lava broken into fragments.
Step-by-step explanation:
Mount St. Helens is a volcano that erupted with great force in 1980. In the year of 1980, there was a major volcanic eruption experienced which was triggered by an earthquake.
The event took place under the area of north face where Mount St. Helens is located. The eruption was so huge that after the explosion there was huge scattering of ash which spread to neighboring states.