It is either A. or B. I don't think that type C. or type D. even exists.
Overpopulation , because it’s overpopulated with stuff that’s already there
Answer:
As a fertilized egg divides, the cells differentiate because they have to become [different] specialized cells to perform different functions.
Explanation:
The molecules of DNA of a human have to be duplicated over end over so that every human’s cell contains a copy of DNA that can be found in a fertilized egg.
When cell differentiates, the embryonic cell becomes a specialized cell. This leads to an expression of gens and that is what dictates the functioning of one cell.
The answer is B. We don't always have exact proof but our observations tell us more than we already know.
