Answer:
A. not washing hands well enough
Explanation:
The reasons/causes for gastroenteritis is getting bacteria basically inside yourself by swallowing or eating it. So not storing food has nothing to do it. Canning food has nothing to do with it. It is you didn't wash your hands well enough.
Information in the image below:
What to do when your brother has an obsession with John F Kennedy and German food? hE iS mEnTaL
answer:
its his life! so love him for who he is