In a convection current, why does cool air take the place of warmer air? a. cool air is less dense than warm air, so it sinks to take the place of rising warm air. b. cool air is denser than warm air, so it sinks to take the place of rising warm air. c. cool air is less dense than warm air, so it rises to take the place of sinking warm air. d. cool air is denser than warm air, so it rises to take the place of sinking warm air. this is science