How does cell division in the vascular cambium contribute to plant growth?

A. Division in the vascular cambium gives rise to new layers of the cortex, which result in thin, flat leaves.
B. Division in the vascular cambium gives rise to new layers of pith, which result in new stem buds.
C. Division in the vascular cambium gives rise to new layers of xylem and phloem, which result in a thicker stem.
D. Division in the vascular cambium gives rise to new layers of vascular cambium, which result in a stronger stem.