Final answer:
Mount Saint Helens is classified as a composite cone or stratovolcano, which is known for having periodic explosive eruptions and is composed of multiple volcanic materials. So the correct answer is Option 4.
Step-by-step explanation:
Mount Saint Helens, an active stratovolcano located in Washington, U.S, is classified as Composite cone or stratovolcano. A composite cone volcano, like Mount Saint Helens, is built of multiple layers of lava, pumice, ash, and other volcanic materials. This type of volcano is typically steep-sided and known for having periodic explosive eruptions. Mount Saint Helens is specifically known for its destructive eruption in 1980 which resulted in the most economically destructive volcanic event in U.S history.
Learn more about Composite cone volcano