Which meristem helps in increasing the girth of plants?

$A$. According to Clowes,the root apex consists of an inverted cup-like structure.
$B$. $A$ low amount of $RNA$,$DNA$,and protein is a characteristic of the waiting meristem.
$C$. Cells of the reserve meristem can divide only when the root apex gets injured.

The cells in the root and shoot apex regions are:

Axillary bud and terminal bud are derived from the activity of

Intercalary meristem is seen in

Apical meristem and intercalary meristem are called primary meristem because?