What is magma in geological terms?

• A. Molten rock below ground
• B. Molten rock above ground
• C. Solid rock beneath surface
• D. Gas or steam

Answer: (A)

Magma is molten rock that is still underground. It forms when rocks melt under high temperature and pressure in the mantle or lower crust, and it can contain crystals and dissolved gases. It sits in magma chambers and can move upward through the surrounding rock. When magma reaches the surface, it erupts as lava, and the gases dissolved in it can drive volcanic activity. The other descriptions refer to lava (molten rock on the surface), solid rock beneath the surface, or gas/steam, none of which are magma.