HIV or Human Immunodeficiency Virus is a viral infection, which directly attacks Leukocytes (white blood cells). Leukocytes are the cells responsible for fighting infections that break past the skin. If the infection is not controlled it can cause a range of disorder's which form a syndrome called AIDS or Acquired Immunodeficiency Disorder Syndrome. When this happen common infection for such thing as a common cold can turn lethal as the body is unable to fight pathogen's effectively.
From what I see, I believe the answer is C. a community health program. I believe this because it says larger, so that must mean community and not family, which is typically smaller.