The process of transformation of meristematic cells into specific permanent tissues is known as cell differentiation.

Option 1: Cell differentiation refers to the process by which cells become specialized and acquire specific structures and functions. It involves changes in gene expression and cell morphology to give rise to different types of cells in the body.

Option 2: Cell division is the process by which cells divide to produce new cells. While cell division is necessary for growth and repair, it does not directly lead to the transformation of meristematic cells into specific permanent tissues.

Option 3: Cell multiplication is similar to cell division and refers to the process of cells dividing and producing more cells. However, it does not specifically address the transformation of meristematic cells into specific permanent tissues.

Option 4: Cell regeneration refers to the process by which damaged or lost cells are replaced with new cells. While cell regeneration can occur through cell division and differentiation, it does not specifically pertain to the transformation of meristematic cells into permanent tissues.

In summary, the correct answer is option 1 - cell differentiation.