Suberin is the main constituent of cork in the higher plants. Which of the following regions in the ground tissue of the plants is associated with suberin?

Endodermis is the inner most layer of cortex represented by a single layer of compactly arranged barrel-shaped parenchyma cells. In the stem, it is meant for storage. In the root, it plays an important role in the movement of absorbed water. Some of the cells in the root endodermis contain secondary thickenings called casparian thickenings formed by a waxy substance called suberin.