Secondary growth occurs as a result of the activity of which two lateral meristems?

A) Vascular cambium and cork cambium
B) Apical meristem and cork cambium
C) Primary meristem and secondary meristem
D) Periderm and cork cambium
E) Apical meristem and vascular cambium

Secondary growth, which leads to an increase in the thickness of plants, primarily occurs due to the activity of two lateral meristems: the vascular cambium and the cork cambium. The vascular cambium is responsible for increasing vascular tissues, adding layers of xylem and phloem, while the cork cambium (or phellogen) produces the cork, contributing to the protective outer layer of the stem.