D. When microspheres split, the genetic coding in self-replicating RNA would pass to the newly formed microsphere.
Explanation - Microspheres are made of proteins. It was observed that when an amino acid was allowed to dry then this amino acid formed proteins and which in turn formed microspheres.
According to the RNA world hypothesis, RNA was the first genetic material and then the DNA became the genetic material of higher organisms during the course of evolution. Microspheres was believed to contain an encoded information with it. During the split of microspheres, this encoded information might transfer to the next generation.