Answer:
C. Joining of self-replication molecules into protocells.
Explanation:
For the origin of life, at least three conditions are needed.
The radiation received from the sun on the early earth must have fulfilled the requirement of mutation. The mutation is necessary for bringing variation in the genetic material thus driving evolution. To protect the self-replicating molecules from the external environment and to keep them together, the molecules must have been enclosed in a membrane barrier, which should be selectively semipermeable, to facilitate the exchange of molecules.