Final answer:
The Option 2: microtubules of the cytoskeleton are responsible for moving organelles and vesicles within the cell, and they also assist in adding cellulose to the cell wall.
Step-by-step explanation:
The fibers of the cytoskeleton responsible for moving organelles and vesicles within the cell are the microtubules.
Microtubules, which are the thickest of the cytoskeletal fibers, perform several critical functions, including guiding organelle movement and serving as tracks for motor proteins that transport 'cargo' such as vesicles from one part of the cell to another.
They are also pivotal during cell division, pulling replicated chromosomes apart to opposite ends of the cell.
Moreover, microtubules play a key role in the addition of cellulose to the plant cell wall by providing a scaffold that directs the orientation of cellulose fiber deposition.
Therefore, the correct answer to the question is Option 2: Microtubules.