Answer:
1- Option (C)
2- Option (A)
3- Option (D)
Step-by-step explanation:
- The magma within the earth's crust are often comprised of various types of materials and dissolved gases. The gases that are commonly present in magma are Water vapor (H₂O) and Carbon dioxide (CO₂). These gases gradually expand and forms bubbles, as the magma rises up and pressure eventually decreases. Some of the gases are escaped into the atmosphere, whereas some remains.
- The pyroclastic flow refers to those materials that are mixed up with rock fragments, volcanic ash and hot air, and that gradually flows along the slope of the volcano. During an explosive volcanic eruption, these materials are ejected and are spread to distant places.
- Calderas are the large crater-like depressions that form due to the subsidence of the mouth of a volcano or due to the eruption of a huge volcano leaving a large bowl-shaped depression. The materials that are present at the apex portion of these volcanoes are mostly comprised of volcanic rocks and tuffs that eventually get collapse.
Hence, the correct answers are mentioned above.