Which phenomenon can result when the pressure of magma builds up in a volcano?

When the pressure of magma builds up in a volcano, it often leads to intense seismic activity. This happens because the magma exerts pressure on surrounding rocks, which can cause fractures and movement within the earth. As the magma accumulates, it generates stress in the Earth's crust, leading to small tremors or even more significant earthquakes as the rocky material struggles to accommodate the growing pressure.

The intense seismic activity is typically a precursor to an eruption, as the shifting and fracturing can result in pathways through which the magma can escape. This buildup of pressure often culminates in an explosive release of magma, gas, and ash, making it a critical part of understanding volcanic behavior and eruption prediction.

In contrast, other options such as a stable volcanic state, no volcanic activity, or gradual land uplift do not correspond to the typical outcomes of increased magma pressure. A stable state suggests there is no buildup of pressure, while no volcanic activity indicates that there are no external signs of magma movement or buildup. Gradual land uplift could occur over time through various geological processes, but it is not a direct result of magma pressure compared to the immediate seismic activity indicating a volatile situation within the volcano.