The correct answer is: shade.
Shade is a dark area that is created when light is blocked by an object. In hot weather, people often lie in the shade of a tree to cool off. The tree’s leaves block the sun’s rays, which makes the area under the tree cooler than the surrounding area.
The other options are incorrect because they do not accurately describe the area under a tree. Shelter is a place that provides protection from the elements, such as rain or wind. Protection is something that keeps someone or something safe from harm. Shadow is a dark area that is created when an object blocks light.
In conclusion, the correct answer to the question “In hot weather I like lying in the …… of a tree” is shade.