The correct option is
D Litchi.
The technique of pegging a branch in soil is known as layering. The tip of the branch is pegged into the soil where it develops adventitious roots. Once the roots develop, the branch is separated from the parent body. The branch which develops the root is known as layer.
Air layering is the process of removing a large branch or section of the trunk of a tree to create another tree. It is practiced in litchi. It involves the following steps.
1) The bark, the cambium, and the phloem layer are removed by cutting away about one inch wide ring of these tissues from around the circumference of the shoot.
2) The xylem is not removed from the area which allows the passage of water and minerals.
3) Rooting material is applied on the girdled material and covered with a polythene bag.
4) The girdled section is allowed to root. After rooting the branch is removed from the tree and planted separately.
So, the correct answer is option D.