Ans.(a) Polychromic methylene blue It is case of cutaneous anthrax in abattoir worker (slaughter house worker). Cutaneous anthrax is also common in dock workers (who carry loads of hides and skin on their bare backs), butchers, farmers, veterinarians, workers involved in meat packing. Pulmonary anthrax is common in workers of wool factories. Intestinal anthrax occur in communities who eat carcasses of animals dying of anthrax. Stains used in case of anthrax: - Gram's stain - Sudan black B - Polychrome methylene blue (stains capsule = M'Fadyean reaction).