An instructor is reviewing Salmonella infections with her class. Which of the following comments indicates that the student needs further review on Salmonella?

"Salmonella has a 48-hour incubation period"

"Salmonella may be spread by spores that form once contaminated blood is exposed to the air."

"Salmonella is a bacterial infection."

"Salmonella symptoms include headaches, abdominal pain, diarrhea, nausea, vomiting, and fever."