The correct option is A Explants
The tissue obtained from a plant to be cultured is called an explant.
Explants can be taken from different many parts of a plant, including
portions of shoots, leaves, stems, flowers, roots, single
undifferentiated cells and from many types of mature cells provided are
they still contain living cytoplasm and nuclei and are able
de-differentiate and resume cell division. This has given rise to the
concept of totipotentency of plant cells. So, the correct answer is 'Explants'.