Which of the following statements about the cytoskeleton is TRUE?

A)All eukaryotic cells have actin, microtubules, and intermediate filaments in their cytoplasm.
B)The cytoskeleton provides a rigid and unchangeable structure important for the shape of the cell.
C)The three cytoskeletal filaments perform distinct tasks in the cell and act completely independently of one another.
D)Actin filaments and microtubules have an inherent polarity, with a plus end that grows more quickly than the minus end.