Ans. (B). chloroplast.
Prokaryotes are first organisms that appeared on the earth. These organisms lack true nucleus and other membrane -bound organelles. According to the studies, cell structure that resembles these prokaryotic organisms are mitochondria and chloroplasts.
This is because, chloroplasts and mitochondria have their own circular DNA to synthesize enzymes and proteins for cellular functions, double-membrane covering, and ribosomes, all of which are also present in prokaryotes.
Thus, the correct answer is option (B).
