Answer: option a. Auer rods are inclusion found most commonly in a myeloblasts.
Explanation: Auer rods are distinctive needle like crystals that are specific for and virtually diagnostic of a myeloid neoplastic clone. The crystal are composed partly of peroxidase proteins that are expressed in myeloid cells. The identification of Auer rods in a blasts is one of the morphological features of myeloblasts.