Chloroplasts and mitochondria are thought to be of prokaryotic origin. One piece of evidence that supports this hypothesis is that these organelles contain prokaryotic-like ribosomes. These ribosomes are probably most similar to ribosomes found __________.
A
free in the cytoplasm of eukaryotes
B
on the rough ER
C
free in the cytoplasm of eukaryotes and on the rough ER
D
free in the cytoplasm of eukaryotes, on the rough ER, and in bacterial cells