Answer:
The correct answer is - B. Lichens.
Step-by-step explanation:
Lichens are one of the pioneer species that can grow on bare rock such as moraine and help make soil for further ecological succession and making ground for other species.
Breaking the bare rocks to convert into the soil is part of the primary succession. Lichens are colonized over these rocks and they contain acid which leads to the breakdown of the moraine and other rocks.