Answer: The correct answer is option C.
Explanation:
In a multi-cellular organism, all cells contain same DNA content. However, not all genes (protein coding sequence of the DNA) are expressed in all the cells.
During development or growth or repair different cells express different sets of genes at a time and repress other genes.
The same is explained in the option C.
Cells do not use the same sections of DNA, that is, genes in the same proportions, that is, expressiveness at the same time in development, which leads to differentiation.
For example, different blood cells are formed or differentiated from the same stem cells. It is because different cells express different genes during the development. consequently, different proteins or traits are developed in different cells which ultimately leads to the production of differentiated cells.