Answer:
heredity
infection
diet
the environment
Step-by-step explanation:
The four options can cause a disease, the definition of disease is a malfunction of the body, there are hereditary diseases such as Huntington´s disease, or infections like when you get a virus or a bacteria, also because of your diet, anemia is mostly caused by your diet, diabetes can also be caused by the diet of the person, or the environment like allergies to certain types of polen in the air.