Age cannot be determined by counting rings in the trees of Temperate evergreen forests, Tropical deciduous forests, Temperate deciduous forests, Tropical evergreen forests

The correct option is D Tropical evergreen forests
A.Temperate deciduous forests - due to maximum seasonal variations annual rings are formed. So the age of the trees can calculated by counting the number of annual rings.
B.Temperate evergreen forests - due to maximum seasonal variations annual rings are formed. So the age of the trees can calculated by counting the number of annual rings.
C. Tropical deciduous forests - due to maximum seasonal variations annual rings are formed. So the age of the trees can calculated by counting the number of annual rings.
D.Tropical evergreen forests - seasonal variations are minimum, annual rings are not formed. Hence the age of the trees cannot be determined by the counting of annual rings.
So, the correct option is ‘Tropical evergreen forests’.