In a dicotyledonous stem,the sequence of tissues from the outside to the inside is

The transverse section of a plant material shows the following anatomical features under microscope $:-$
$(a)$ Collenchymatous hypodermis
$(b)$ Sclerenchymatous pericycle located just above phloem bundles in semi-lunar patches.
$(c)$ Vascular bundles are arranged in a ring.
$(d)$ Vascular bundles are conjoint & open.
Plant material should be :

Identify $A, B, C$ and $D$ in the given figure of a monocot stem cross-section.

The lacunae in the vascular bundles of a monocot stem is:

Vascular bundles surrounded by a sclerenchymatous bundle sheath is a feature of

The vascular bundles in the stem of monocots are typically