Question

which is the most important change that marks the pubery

Answer 1

Most important change are seen during puberty is increased in breast size .

Answer 2

In females the most important change is menstruation
and in males the most important is growth of facial hair
besides these there are other chnges also
like growth of pubic hairs
growth of chest area in females(breast)
growth of hairs in armpits
voice of males becomes more heavy
.....hope it helps