Answer:
Differentiation.
Step-by-step explanation:
Cell differentiation may be defined as the process in which the cell changes into another cell type from the one cell type. Differentiation is continuous in stem cells of the adults.
During the process of cell differentiation, the cells become restricted to their potential development. The cells determines its fate and start performing a specific function in the cell differentiation. Specific proteins and transcription factors are required for the process of cell differentiation.
Thus, the correct answer is option (d).