number of mitochondria presence of a nucleus structure of the cytoskeleton salt concentration of cytoplasm
I gave my students this multiple choice question: Research has shown that specialization of stem cells into specific cell types results, in part, from cell shape. What provides a specialized cell with its shape?

Only one answer is correct among these 4 choices:
- number of mitochondria
- presence of a nucleus
- structure of the cytoskeleton
- salt concentration of cytoplasm

Could you tell me which one is correct?

structure of the cytoskeleton