The vascular cambium is ..........

$I.$ Annual rings are formed as a result of seasonal environmental conditions.
$II.$ Tracheids/vessel elements are larger during periods when water is abundant.
$III.$ Tracheids/vessel elements have thicker walls during periods of water deprivation.
$IV.$ Wood formed in previous years is always darker than newer wood.
Select the combination of correct statements from the options given below.

This wood is light in color,has low density,and consists of a large number of xylem elements with wide vessels.

What does the following figure represent?

Secondary growth occurs in .........?

Seasonal activity of vascular cambium is influenced by many factors,except