Answer: A. Primary
Step-by-step explanation:
A pioneer species is the one which colonize in an area where no living species previously existed before. It makes the environment suitable for the survival of the other species.
A primary succession occurs in a region where no living species existed before. The environment is unsuitable for the growth of diversity of species.
A pioneer species like lichen will grow over the rocks, will secrete acids which will wither the rocks. This will help in soil formation. The soil will facilitate the growth of new plants. Hence, the pioneer species will initiate the primary succession.