Auer rods are seen in:: (A) Acute myeloid leukemia., (B) Chronic myeloid leukemia., (C) Iron deficiency anaemia, (D) Hodgkin’s disease.
Answer is A. Some of the commonly employed cytochemical stains, as an aid to classify the type of acute leukemia, are-

Myeloperoxidase: positive in immature myeloid cells containing granules and Auer rods but negative in M0 myeloblasts.
Sudan black: Positive in immature cells in AML.
Periodic acid Schiff (PAS): Positive in immature lymphoid cells and in erythroleukemia (M6).
Non-specific esterase (NSE): Positive in monocytic series (M4 and M5).
Acid phosphatase: Focal positivity in leukemic blasts in ALL and diffuse reaction in monocytic cells (M4 and M5).