Measurement involve in forest mensuration:

A.The determination of the dimension, form, volume, age and increments of logs, single trees, stands or whole (B.C.F.T.)
B.It is art of taking measurements for compiling data. In forestry this art is applied / used for measuring the forest produce e.g. Timber, firewood, standing trees or crop
C.Both (a) & (b)
D.None of these