**Core Concept**
The process being described is a fundamental aspect of developmental biology and tissue engineering, where stem cells differentiate into specialized cells to form tissues and organs. This process involves a series of complex molecular and cellular interactions that ultimately lead to the formation of cells with specific functions and characteristics.

**Why the Correct Answer is Right**
The transformation of stem cells into cells characteristic of other tissues is called differentiation. This process is tightly regulated by a combination of intrinsic factors, such as transcription factors, and extrinsic factors, such as growth factors and hormones. The differentiation process involves a series of cellular changes, including changes in gene expression, protein synthesis, and cellular morphology. For example, during embryonic development, stem cells in the neural crest differentiate into neurons, glial cells, and other cell types that form the nervous system.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is not a recognized term in the context of stem cell biology.
**Option B:** This option is incorrect because it refers to a process that is not directly related to the transformation of stem cells into specialized cells.
**Option C:** This option is incorrect because it is a term that is not commonly used in the context of stem cell differentiation.

**Clinical Pearl / High-Yield Fact**
One important aspect of stem cell biology is the concept of plasticity, which refers to the ability of stem cells to differentiate into multiple cell types. This concept has significant implications for regenerative medicine and tissue engineering.

**Correct Answer: D. Differentiation.**