What is the direct control on whether a volcano will erupt violently or quietly send out a few flows?

Question

Quizplus · Accepted Answer

The composition of the magma, its temperature, and dissolved gas content all directly affect the behavior of a volcano during an eruption. If a volcano's magma is more viscous, it will tend to erupt more violently, while magma with lower viscosity will tend to flow more easily. The temperature and dissolved gas content also play a role in how easily magma can flow and how explosive an eruption can be. The other options (B, C, and D) do not have a direct control on the eruption style of a volcano.

What Is the Direct Control on Whether a Volcano Will