On the basis of variation in form, structure, origin and development, sclerenchyma may be
Fibres
Sclereids
Either $(a)$ or $(b)$
Both $(a)$ and $(b)$
Closed Vascular bundles lack
Stomata in grass leaf are
Root hairs are found
Lenticels are involved in :
The specialised epidermal cells present in the vicinity of guard cells are called