Primary succession is development of communities on

The correct option is A Newly exposed habitat
When the ecosystem in an area changes, it is called ecological succession. New species come into existence at this place. Apart from this, ecological succession is of 2 types. One is primary succession, in which a barren land with no species affiliation shows development of a new species. And another is secondary succession where the species develop again in a land which was previously occupied by different organisms and was destroyed due to certain reasons.

So, option A is the correct answer.