The correct answer is option B) Cristae.
The cristae are the structures formed by the folding of the mitochondiral inner membrane. The crista are only found in the mitochondria and causes the internal division of the mitochondria. The chlorophylls are the pigments found in the chloroplasts of the Chlorophyll. The thalakoid are structures present in the chloroplast, lined by the thalakoid membrane. The stroma is the fluid present in the chloroplast.