Meat from chickens contaminated with salmonella bacteria can cause serious food poisoning. Capsaicin, the chemical that gives chili peppers their hot flavor, has antibacterial properties. Chickens do not have taste receptors for capsaicin and will readily eat feed laced with capsaicin. When chickens were fed such feed and then exposed to salmonella bacteria, relatively few of them became contaminated with salmonella. In deciding whether the feed would be useful in raising salmonella-free chicken for retail sale, it would be most helpful to determine which of the following? ['Whether eating capsaicin reduces the risk of salmonella poisoning for humans', 'Whether appropriate cooking of chicken contaminated with salmonella can always prevent food poisoning', 'Whether feeding capsaicin to chickens affects the taste of their meat', 'Whether capsaicin can be obtained only from chili peppers']