Why do volcanoes erupt?

Answer: Magma pressure forces it up

Magma pressure forces it up ✓ — Correct! Deep underground, rock melts into magma due to extreme heat and pressure. Magma is less dense than surrounding rock, so it rises. As it rises, dissolved gases expand and pressure builds. When pressure exceeds the strength of the overlying rock, the volcano erupts! Magma can reach the surface through cracks or weak spots in Earth's crust.

Ocean water seeps in and boils — Wrong. Ocean water doesn't seep into magma chambers to cause eruptions. Magma chambers are sealed by solid rock, and any water that did contact magma would flash to steam instantly—not build up enough pressure to cause an eruption. The real driver is pressure from rising magma.

Earthquakes trigger eruptions — Wrong. Earthquakes don't cause eruptions—both are symptoms of tectonic activity. Volcanic eruptions are driven by magma pressure building until it breaks through rock. Earthquakes and eruptions often occur together at plate boundaries, but one doesn't cause the other.