Answer:
The correct answer is option A. All cells come from previously existing cells.
Step-by-step explanation:
According to the cell theory presented Schleiden and Schwann. The cell theory is universally accepted now. It has 3 major points that are all organisms are made up of structural and functional unit cell.
They can be multi cellular or unicellular. Cell come from the cells that are already present.
Thus, the correct answer is option A. All cells come from previously existing cells.