Answer:
The correct answer would be C) development of organs for transplantation.
Cell differentiation refers to a process by which a cell becomes specialized to perform a specific function. For example, a liver cell, blood cell, muscle cell et cetera.
In multi-cellular organisms, life starts with a single cell (zygote) which then divide and differentiate into various types of cells. The specialized cells synchronize to form tissue which then form a particular organ.
Thus, regulation of cell differentiation can lead to development of specific organ which can be used for transplantation.