The correct option is C AIDS
AIDS or Acquired Immune Deficiency Syndrome is a type of sexually transmitted disease, caused by the Human Immunodeficiency Virus (HIV). Fragile X syndrome occurs due to a type of non-frameshift mutation in which, a CGG triplet is repeated more than 200 times on a gene of the X chromosome. Down syndrome is caused due to nondisjunction of the 21st pair of homologous chromosomes, resulting in an extra 21st chromosome in the affected individual. Cancers could be caused by mutations in the genome resulting from certain environmental factors such as radiations and cigarette smoke.