Answer:
B) Over time, much of their nucleic acid has migrated to the host cell nucleus
Explanation:
The origin of chloroplasts and mitochondria is explained via endosymbiosis theory: they  originated as prokarytoic symbionts. The host cell acquired genetic information from them and “took it up” by lateral gene transfer. Those genes (now located in the eukaryotic cell nucleus-nuclear genome) encode the great majority of chloroplast and mitochondrial proteins, as well as many proteins of the nucleus and cytosol. Â
Yet ,chloroplasts and mitochondria retained some of the genes in their genomes.