A'a, Pillow, and Pahoehoe are three kinds of this.

• A. Magma
• B. Ash
• C. Lava
• D. Gas

Answer: (C)

These terms describe how lava looks as it erupts and flows, not what sits underground or what gets erupted as particles. A’a, Pahoehoe, and Pillow are all forms of lava—molten rock that has reached the surface and cooled in different ways. A’a is rough and jagged, Pahoehoe is smooth and ropey, and Pillow lava forms when lava erupts underwater, cooling into rounded pillow shapes. That’s why lava is the best fit.

Magma is molten rock beneath the surface, which becomes lava once it erupts. Ash is fine volcanic particulates ejected into the air, not the molten rock flow. Gas refers to volcanic gases released during activity, not the molten rock itself.