Which of the following are derived from the secondary meristems?

The anatomy of springwood shows some peculiar features. Identify the correct set of statements about springwood.
$(a)$ It is also called as the earlywood
$(b)$ In spring season cambium produces xylem elements with narrow vessels
$(c)$ It is lighter in colour
$(d)$ The springwood along with autumnwood shows alternate concentric rings forming annual rings
$(e)$ It has lower density
Choose the correct answer from the options given below:

Annual rings are produced due to the activity of:

In dicot roots,what is the very first event that occurs during the initiation of secondary growth?

In the dicot root,the vascular cambium originates from:

The activity of cambium in plants is under the control of