The activity of cambium in plants is under the control of
a)	Many physiological factors
b)	Many environmental factors
c)	Only water availability
d)	Both (a) and (b)

(d)

Both (a) and (b).

The activity of cambium is under the control of many physiological and environmental factors. In temperate regions, the climatic conditions are not uniform through the year. In the spring season, cambium is very active and produces a large number of xylary elements having vessels with wider cavities. The wood formed during this season is called spring wood or early wood