insect bites. contaminated food. genetically from parents. pathogens in the air.
I gave my students this multiple choice question: Infectious diseases can be passed from organism to organism by all of the following except

Only one answer is correct among these 4 choices:
- insect bites.
- contaminated food.
- genetically from parents.
- pathogens in the air.

Could you tell me which one is correct?

genetically from parents.