Question

the diameter of woody stem is continuously increasing because of which structure
a) vascular cambium
b) epidermis
c) phellogen
d) endodermis

Answer 1

Hey Buddy!
The answer is Vascular Cambium.
It is a meristematic Tissue.
It is responsible for the growth of The plant laterally or from girth.

Hope it helps you!

Answer 2

${\mathcal{\huge{\red{\underline{ANSWER}}}}}$

$<b> As the diameter of woody stem is continuously increasing then the structure responsible for it is <u>repeated division which takes place in epidermis</u>$