Identify the correct statements :
A. Lenticels are the lens-shaped openings permitting the exchange of gases.
B. Bark formed early in the season is called hard bark.
C. Bark is a technical term that refers to all tissues exterior to vascular cambium.
D. Bark refers to periderm and secondary phloem.
E. Phellogen is single-layered in thickness.
Choose the correct answer from the options given below:

A and D are correct. B, C and E are incorrect.
A. Lenticels are the lens-shaped openings formed during secondary growth, permitting the exchange of gases.
B. Bark that is formed early in the season is called early or soft bark. Towards the end of the season, late or hard bark is formed
C. Bark is a non-technical term that refers to all tissues exterior to vascular cambium (phloem + periderm).
D. Bark refers to all the tissues present outside the vascular cambium (periderm and secondary phloem) but
primary phloem crushed by pericycle cells.
E. Phellogen is a couple of layers thick. It is made of narrow, thin-walled and nearly rectangular cells. Phellogen
cuts off cells on both sides. The outer cells differentiate into cork or phellem while the inner cells differentiate into secondary cortex or phelloderm.