A type of plant budding in which a small patch of bark bearing a scion bud is fitted into a corresponding opening in the stock.

Correct option is A

The correct answer is (a) Patch budding. 
This method involves removing a rectangular patch of bark from the rootstock and replacing it with a patch of bark of the same size containing a bud of the desired cultivar. The patch from the scion is fitted into the opening in the stock, and the union is secured to ensure proper healing and growth.

Other Options:
(b) Ring Budding: 
· This technique involves removing a ring of bark from the rootstock and replacing it with a ring of bark containing a bud from the scion. It is not as commonly used as patch budding.
(c) Chip budding: 
· In chip budding, a small chip of wood with a bud is removed from the scion and inserted into a corresponding cut in the rootstock. It is useful for species where the bark does not separate easily from the wood.
(d) T budding: 
· This method involves making a T-shaped cut in the bark of the rootstock and inserting a bud from the scion into the cut. It is commonly used for many fruit trees and roses.
(e) Shield budding: 
· Similar to T budding, shield budding involves making a cut in the shape of a shield in the rootstock and inserting a bud from the scion. It is another common method for budding fruit trees and roses.