Answer:
C. They descended from several prokaryotic ancestors that were unrelated to one another.
Explanation:
According to many experiments, scientists believe that the first organism on the earth is prokaryote. With the passage of time from these prokaryotes, eukaryotes are evolved. Prokaryote is a type of organism which have no true nucleus and organelles such as mitochondria, ribosome, lysosomes, endoplasmic reticulum and golgi bodies etc are absent while eukaryotes are those organisms which have true nucleus and organelles are also present.