Microtubules are the constituents of (a) centrioles, spindle fibres and chromatin (b) centrosome, nucleosome and centrioles (c) cilia, flagella and peroxisomes (d) spindle fibres, centrioles and cilia.
Option d is correct . Microtubules are unbranched hollow submicroscopic tubules of protein tubulin which develop on specific nucleating regions. It can undergo quick growth or dissolution at their ends by assembly or disassembly of monomers.
