Respuesta :
The right answer is 1) biological agents .
All biological, chemical and physical hazards must be considered in the food chain.
Examples of biological agents: Hepatitis A and E viruses, Rotaviruses, Clostridium, Bacillus cereus, as well as parasites (Cryptosporidium, Entamoeba hystolytica, Giardia, Ascaris, Tenia ....).