Answer: Option A
Step-by-step explanation:
During the cellular division the number of cells in an organism increases. The cells proliferate form one to two and two to four and so on.
The basic level of the body is made of cells and the body initiates from a single cell and grows into a whole body.
This is due to increase in the cell number of the body. The cells gets divided inside body by the DNA replication.
This is how the whole organism grows from the single cell.