In cell biology, a centriole is a cylindrical cell structure composed mainly of a protein called tubulin that is found in most eukaryotic cells. It is made from nine triplets of microtubules formed into a cylinder. The pattern of the microtubules for a ring of 9 microtubules known as "triplets" and the microtubules are attached to other two partial microtubules. Thus the correct answer is option A.