Cross-contamination occurs when A.
food handlers get sick after eating contaminated food at a foodservice operation.
B.
food handlers prep ready-to-eat food before prepping raw food.
C.
food handlers place contaminated cleaning equipment on food-contact surfaces.
D.
food handlers use different colored cutting boards for different foods.
E.
food handlers store ready-to-eat food above raw food items.

Investigator a has biological specimens that are coded and linked to identifiers of the source individuals. investigator a provides the specimens to investigator b but does not provide the individual identifiers. investigator b agrees not to re-identify the source individuals. is investigator b's research using the biospecimens human subjects research according to the definition of human subjects research in the federal regulations?