Answer: B. The prokaryotic cells are smaller than the eukaryotic cells.
Step-by-step explanation: Its just the simple process of elimination. Prokaryotic cells lack of a lot of things, including mitochondria, so it couldn't be option C. BOTH prokaryotic and eukaryotic cells have cytosol AND ribosomes, so the answer couldn't be D or A, and you're left with option B. Meaning option B is the correct choice.