Which nutrient assists in the overall vitality and growth of plant cells through growth and division?

Phosphorus plays a crucial role in the vitality and growth of plant cells, primarily due to its involvement in key biological processes. It is a fundamental component of essential molecules such as ATP (adenosine triphosphate), which serves as the energy currency of cells. This means that phosphorus is vital for the energy transfer processes necessary for various cellular activities, including growth and division.

Moreover, phosphorus is an integral part of nucleic acids (DNA and RNA), which are critical for the replication and expression of genetic material. Without sufficient phosphorus, not only can energy transfer be hindered, but the synthesis of genetic material and the subsequent growth processes can be severely affected, leading to stunted growth or poor development.

In addition, phosphorus influences root development, flowering, and fruiting, making it essential for overall plant vigor. The availability of phosphorus in a plant's environment is directly linked to its ability to establish a healthy root system and efficiently utilize other nutrients, further ensuring robust growth and development. Thus, phosphorus’s role in promoting plant cell vitality and facilitating growth and division makes it the correct answer.