C. Joining of self-replication molecules into protocells.
Explanation:
For the origin of life, at least three conditions are needed.
there must have been a supply of replicators, that is, self-replicating molecules.
copying of these replicators must have been subject to error through mutation.
the system of replicators must have required a continuous supply of free energy and partial isolation from the general environment.
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.
