The correct answer is:
C. Two eukaryotic cells could differ in the number and types of organelles they contain.
Explanation: Eukaryotic cells can exhibit significant variability in their organelles depending on their specific functions and the type of organism they belong to (such as plant cells, animal cells, fungi, etc.). For example, plant cells contain chloroplasts for photosynthesis, while animal cells do not.
Options A and B are incorrect because all eukaryotic cells have cytoplasm and a cell membrane. Option D is incorrect because eukaryotic cells do not contain prokaryotes; rather, they are distinct types of organisms.