Explanation:
everything can be found in the picture
I think the answer is d not a 100 % sure
Convection currents occur in the MANTLE. The mantle is the second layer of the earth after the crust. The mantle is approximately 2900 km thick. Convection currents are triggered or fueled by the heat from the Earth's core.
The part of the mantle closest to the core gets heated. It then becomes less dense than the layers above so it rises. When this rising plume interacts with the crust it cools and becomes more dense than the layers below and so it sinks and this circular motion continues to form convection currents.
4) Polaris
Stars emit light with energy generated by nuclear fusion, think of the Sun as an example. Polaris is a star, it's the brightest star in the little bear constellation, and therefore the correct answer.