Explanation:
The cytoskeleton is composed of proteinaceous filaments that provide structural support, shape, and facilitate movement within the cell. These filaments include microtubules, actin filaments (microfilaments), and intermediate filaments.
Other options:
Calcium carbonate granules: Found in some plant cells (e.g., in the vacuoles of certain plant cells), but not part of the cytoskeleton.
Callose deposits: A carbohydrate polymer found in plant cell walls, not part of the cytoskeleton.
Cellulose microfibrils: Found in plant cell walls, not in the cytoskeleton.
Thus, proteinaceous filaments is the correct answer.