Answer:
O As the air around the campfire is heated and becomes less dense, it rises and moves upward.
Explanation:
This is true because, the convection transfer needs the particle of elements to transport the heat from where it is in abundance to where it is in less abundance. Just like a water boiling becoming hot at the point closer to the fire than the top of the pot, so also will the air around campfire transfer heated air from the place closer to the campfire to upwards aware from the fire.