Answer:
A) microtubules
Explanation:
The diameter of the cytoskeletal fibers are as follows -
Hence ,
From the above data , Microtubules have the largest diameter , it is made up of tubulin proteins which are arrange in the form of a straw - like tube which is hollow from inside , and each of the tubuline protein consists of two sub units i.e. alpha - tubuline and the beta - tubuline .