Provide your best answer for the following question. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The question is: In eukaryotic organisms, microtubules give cells structure, and microfilaments help the cell contract and move. Together, they combine to perform functions similar to what two human body systems?
the skeletal and muscular systems
Skeletal and Muscular.