Final answer:
Tip layering is the type of layering done on stems above ground. In this method, the tip of the stem is buried in soil to encourage root growth and the development of new buds.
Step-by-step explanation:
The subject of question is science.
The type of layering done on stems above ground is b) tip layering.
In tip layering, the tip of the stem is buried in soil to encourage the growth of roots. This method is commonly used in plants such as strawberry plants. By burying the tip of the stem, new buds will form and develop into a new plant.