Q.Consider the following statements
In spring season vascular cambium
i. is less active
ii. produces a large number of xylary elements
iii. forms vessels with wide cavities of these,
a.

Annual rings (often loosely called growth rings, though not every growth ring is strictly annual) are the visible concentric bands seen in a tree trunk's cross section, formed by the vascular cambium's seasonally varying activity in regions where the climate itself varies sharply through the year. In spring, the cambium is highly active and produces a large number of xylary elements with wide lumens and comparatively thin walls - pale, lower-density spring wood or early wood. As the season moves toward winter, cambial activity slows and produces fewer, narrower-lumened, thicker-walled elements - darker, higher-density autumn wood or late wood. One band of spring wood plus the adjoining band of autumn wood, both laid down in a single year, together constitute one annual ring, made visible to the eye specifically by the density contrast (the higher density of the late-wood band).

Distinct annual rings form best where seasonal climatic variation is sharp, so they are most pronounced in temperate plants and least distinct in seashore and desert plants, where conditions stay comparatively uniform year-round. Not every growth ring is a genuine once-a-year annual ring, however: adverse conditions occurring within a single growing season - drought, frost, defoliation, flood, mechanical injury or biotic factors - can trigger the formation of more than one growth ring within that one year; such extra bands are called pseudo- or false-annual rings. Counting genuine annual rings to determine a tree's age is called dendrochronology, and the same ring record supports several other applications: assessing timber quality, cross-verifying radiocarbon dating, reconstructing past climate and archaeological chronology (the specialised sub-field of dendroclimatology), and providing evidence in forensic investigations.