Sinking of material in a convection current is linked with which condition?

Correct answer: Material becoming cool and heavy

The direct answer is A, material becoming cool and heavy. In a convection current, heating usually makes material expand and become less dense, so it rises. When the material moves toward a cooler region, it loses heat. Cooling makes it denser, or heavier for the same volume, and gravity causes it to sink. This rising-and-sinking cycle continues as long as there is a heat difference. Option A is correct because cooling and increased density explain downward movement. Option B is wrong because becoming light would normally make material rise, not sink. Option C is wrong because cloud formation is an atmospheric water process and does not describe mantle convection. Option D is meaningless in physical science; material cannot become a song. Memory cue: hot and light rise; cool and dense sink.