The correct option is: (b) calyptrogen
Explanation:
If the root cap is independent in origin it arises from a special layer called the calyptrogen. In case it is not independent in origin. It arises from the dermatogen. Dermatogen is the region or histogen of single layer of outermost cells formed from the apical meristem. Dermatogen gives rise to epidermis of stem and other aerial parts. In root it gives rise to epidermis and root cap or calyptrogen. Calyptrogen is meristematic and forms root cap.
