Cambium activity is

The bark of tree comprises

Lenticels are involved in

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:

Heartwood differs from sapwood in