The correct option is D bulliform cells
Bulliform cells are found on the upper epidermis of the monocot leaves and help in the rolling of leaves.
Bundle sheath cells are those that are found surrounding vascular bundles, as found in monocot stems and in both dicot and monocot leaves. They could be collenchymatous or sclerenchymatous.
Sclereids are the cells of sclerenchyma tissue.
Stele is made up of all the layers within the endodermis such as the pericycle, xylem , phloem and the pith