The correct option is A Micropropagation
Micropropagation is the practice of rapidly multiplying stock plant material to produce a large number of progeny plants, using modern tissue culture methods.
Grafting is the technique whereby tissues from one plant are inserted into those of another so that the two sets of vascular tissues may join together.
Layering is a means of plant propagation in which a portion of an aerial stem grows roots while still attached to the parent plant and then detaches as an independent plant.