The right answer is organisms.
In biology, the growth of an organism is an increase in size, and volume.
In living organisms, as in humans, growth is often regulated by growth hormones.
The growth of an organism can be done by:
* Increasing the number of cells by dividing the cells,
* Increase in the volume of each cell (which is the cause of the growth of fatty tissue),
* Increased volume of the extracellular matrix (important in bone growth).