Antigens are found on cancer cells and the cells of transplanted organs, and anything that can trigger an immune response is called an antigen. Given these facts, what can trigger immune response among the following options:
- harmful substances
 - Transplanted organs
 - desire
 - an area swollen with pus
 - death
 - pain
 - colors of the spectrum
 - Contaminated wounds


 

  Transplanted organs       