The correct option is B Cancer
Interferons are a group of signaling proteins made and released by the host cells in response to the presence of pathogens, such as viruses, bacteria, parasites or tumor cells. Interferons do not directly kill viral or cancerous cells; they boost the immune system response and reduce the growth of cancer cells by regulating the action of several genes that control the secretion of numerous cellular proteins that affect growth. Interferon therapy is used (in combination with chemotherapy and radiation) as a treatment of cancers.