2. When volcanoes erupt, they emit large plumes of hot smoke and ash, which can spread and cover miles of sky. Which process lifts the hot, black clouds into the sky?
A. Radiation that causes thermal energy to transfer into the clouds and hold them
together
B. Conduction that causes thermal energy to pass from the smoke into the ground
C. Conduction that causes warmer air to spread and cooler air to condense into clouds
D. Convection that causes warmer air to rise and cooler air to sink into its place