Answer:
B. Large buildup of pressure from gases
Explanation:
The composite volcanoes are volcanoes that are characterized with felsic magma. This type of magma is highly to intermediately viscous. The silica content is high. This results in much denser magma that manages to trap the gases in it instead of them living freely into the atmosphere. As the magma comes toward the surface, the temperature and pressure change significantly, so the built up gases in it manage to cause strong explosion, which in turn results in explosive and effusive eruptions of these volcanoes.
