In Betula the bark is
A) Ring bark used for writing
B) Scaly back used for writing
C) Ring bark used as a masticatory
D) Ring bark used as a spice

Hint: Most tree species have bark that is unique in structure and appearance.The inner soft bark is produced by the vascular cambium. The outer bark, which is mostly dead tissue, is the product of the cork cambium.

Complete Answer:
Let us start with knowing what actually a bark is-
Bark, found in woody plants, are the tissues external to the vascular cambium, the term is also employed more popularly to refer to all tissues outside the wood. The inner soft bark, alternatively known as the bast, is produced by the vascular cambium. The outer bark, which is mostly dead tissue, is the product of the cork cambium.
The bark mainly consists of secondary phloem tissue whose innermost layer conveys food from the leaves to the rest of the plant. The outer bark, which is mostly dead tissue, is the product of the cork cambium (also known as phellogen).
Now, we will know about the types of barks there are in nature depending on the arrangement of tissues. They are the following-
1) Scaly bark in which the subsequent periderm layer develops as overlapping scales. Patches of bark form and can be shed. It is found in Eucalyptus and Psidium.
2) Ring bark used for Spices constitute the bark of a plant which is used as a culinary ingredient. These bark type spices are highly flavoured and impart taste to the food it is mixed with. The two very common Bark type spices are Cinnamon and Cassia.
In Betula, bark is present in the form of sheets, called ring bark. It is used for writing.

Hence,the correct answer is option A (Ring bark used for writing).

Note:Both inner bark and wood are generated by the vascular cambium layer of cells.In older trunks the thick, deeply furrowed bark breaks into irregular plates.