An example of chromoprotein is: (A) Hemoglobin, (B) Sturine, (C) Nuclein, (D) Gliadin
Answer is A. Chromoproteins: These are proteins with coloured prosthetic groups. Hemoglobin (Heme, red); Flavoproteins (Riboflavin, yellow), Visual purple (Vitamin A, purple) are some examples of chromoproteins.
Reference: Vasudevan 7th  ed, pg 43