Which statement about the May, 1980, eruption of Mount St. Helens is false?

Question

Quizplus · Accepted Answer

During the May 1980 eruption of Mount St. Helens, the mountain peak was not substantially built up by new lava flows and pyroclastic debris. Instead, the eruption caused the mountain's summit to collapse and lose nearly 1,300 feet in height. The most powerful explosive event was indeed preceded by a massive landslide, plumes of ash did rise high into the atmosphere, and mudflows accompanied the major eruptive events.

Which Statement About the May, 1980, Eruption of Mount St