60. What can be inferred from the above passage? (A) Human beings will not get influenza A because the disease is only infectious to domestic poultry. (B) Once influenza A viruses spread out, a burst of deadly disaster will happen to chickens, ducks, or geese raised domestically. (C) Smallpox could occur again mainly because victims take medicine without guidance or permission of clinic doctors. (D) It is legitimate to employ antibiotics as growth promoters in agriculture.