The definition of hygiene says cleanliness. A does not have to do with that. B does because keeping that clean prevents food diseases like salmonella. C has nothing to do with hygiene. D has nothing to do with being clean. So the answer would be B. I hope this helps!
The correct letter answer is A or C. Choose whichever one you want. I think it's C, but you can consider A also. :)
The process of infection can be broken down into stages, each of which can be blocked by different defense mechanisms. In the first stage, a new host is exposed to infectious particles shed by an infected individual. The number, route, mode of transmission, and stability of an infectious agent outside the host determines its infectivity. Some pathogens, such as anthrax, are spread by spores that are highly resistant to heat and drying, while others, such as the human immunodeficiency virus (HIV), are spread only by the exchange of bodily fluids or tissues because they are unable to survive as infectious agents outside the body.